• Title/Summary/Keyword: Science and technology issues

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A Study on the Improvements of eBook Services for Children in the Public Library (공공도서관 어린이 전자책 서비스 개선방안에 관한 연구)

  • Baek, Ji-Won
    • Journal of Information Management
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    • v.43 no.1
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    • pp.63-87
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    • 2012
  • This study aims to analyse the actual condition of the ebook services and propose the improvements of ebook services for children in the Korean public library. For this purpose, the current condition of the ebook services in the public libraries were analyzed and categorized by three criteria. Secondly, the ebook use analysis was conducted using PCs and mobile devices in terms of access to ebook library site, searching method, contents type and viewer, lending process, and user help. As a result of the analysis, several issues such as the difficulty in access to ebook site, the complexity of setting and usage depending on the file format, the insufficient user guide, the relatively lower quality service than the commercial's, and the lack of retrieval functions specialized for the ebook were presented. The improvement plan for the ebook services, especially for children in the public library was suggested.

Farm Animal Mortality Management Practices in Sunchon-si (순천시의 폐사가축 처리실태에 관한 연구)

  • Hong, Ji-Hyung
    • Journal of Animal Environmental Science
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    • v.16 no.3
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    • pp.245-252
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    • 2010
  • Disposal methods of managing carcass in Korea livestock production systems include burying, digesting, rendering, carcass dumping to manure pile, dead animal disposer and mini-incinerator. Burying was usually the most practical method of carcass disposal in our livestock farms. Burying, carcass dumping to manure pile, dead animal disposer and mini-incinerator may have environmental regulatory and economic liabilities when used as a means of carcass disposal. In many cases in this survey, these disposal methods offer a poor choice for the producer due to individual site conditions, geology, cost, air emissions, rendering plants. A survey questionnaire that addressed the issues to livestock producers was prepared. The questionnaire addressed two main topics as follows: 1) types of livestock and generation amounts of carcass 2) Number of breeding animals and disposal methods of livestock mortality. A total of 36 livestock producers were interviewed. The results of obtained in this survey were summarized as follows: The number of breeding poultry, swine, beef cow and dairy cow was 251,000, 2,600, 142 and 92 heads per year and the generation amounts of annually carcass was 0.46, 15.32, 0.36, 1.36 tons per year of each poultry, swine, beef cow and dairy cow farms, respectively. The disposal methods of carcass were burying (42%), carcass dumping to manure pile (36%), rendering (8%), incineration (6%), digesting (6%), carcass disposer (2%), respectively. These results can be used as basic information to establish the standard of carcass composting facility.

What Is Cultured Meat? (배양육이란 무엇인가?)

  • Huh, Man Kyu
    • Journal of Life Science
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    • v.31 no.6
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    • pp.587-594
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    • 2021
  • By 2050, 70% more food will be needed to fulfill the demands of a growing population. Among the solutions, cultured meat or clean meat is presented as a sustainable alternative for consumers. Scientists have begun to leverage knowledge and tools accumulated in the fields of stem cell and tissue engineering in efforts aimed at the development of cell-based meat. Cultured meat has to recreate the complex structure of livestock muscles with a few cells. Cells start to divide after they are cultured in a culture medium, which provides nutrients, hormones, and growth factors. An initial problem with this type of culture is the serum used, as in vitro meat aims to be slaughter free. Thus, it is contradictory to use a medium made from the blood of dead calves. The serum is expensive and affects to a large extent the production cost of the meat. A positive aspect related to the safety of cultured meat is that it is not produced from animals raised in confined spaces and slaughtered in inhumane conditions. Thus, the risk of an outbreak is eliminated, and there is no need for vaccinations and animal welfare issues. The production of cultured meat is presented as environmentally friendly, as it is supposed to produce less greenhouse gas, consume less water, and use less land in comparison to conventional meat production.

Development of Convergence Education (STEAM) Program for High School Credit System (고교학점제를 위한 융합교육(STEAM) 프로그램 개발)

  • Kwon, Hyuksoo;Kim, Eojin;Kim, Jaewoon;Min, JaeSik;Bae, SangIl;Son, MiHyun;Lee, Hyonyong;Choi, JinYoung;Han, MiYoung;Ham, HyungIn
    • Journal of Science Education
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    • v.46 no.1
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    • pp.93-108
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    • 2022
  • The purpose of this study is to develop a STEAM program that can be used in the high school credit system to be fully implemented in 2025, and to examine its validity and effectiveness. The STEAM program analyzed the 2015 revised curriculum centering on science, technology, and engineering through the 2015 revised curriculum analysis, and then selected the five latest issues: hydrogen fuel, climate crisis, data science, appropriate technology, and barista. In accordance with this self-developed program development format (frame), it was developed for seven months through a process of group deliberation. The draft of the STEAM program for 29 sessions of five types, developed to indirectly experience the career path and occupation of high school students, was verified through consultation with 2 STEAM education experts. It was applied at five different high schools for a pilot implementation. As a result of the pilot application, it was confirmed that the students' STEAM attitude significantly improved in the post-test than the pre-test, and the students' high satisfaction with the program was confirmed. In addition, through an interview with the pilot application teacher, it was positively evaluated that 'the content and level of the program are suitable and through experience solving real-life problems, you can apply the content knowledge of related subjects and have an opportunity to experience careers.' Based on the results of the pilot application, the high school credit system STEAM program for students and teachers was finally completed in 29 lessons of five types. Through this study, the development and operation of the next-generation STEAM program that can be applied in the high school credit system should be actively developed, and a plan to improve teachers' professionalism so that the high school credit system can be established and operated properly for blended classes triggered by COVID-19. The necessity of design was suggested. This study is expected to be used as basic data for the development and operation of STEAM programs in the high school credit system, which will be fully implemented in 2025.

Watt, Who is he? (와트, 그는 누구인가?)

  • Choi, Jun-Seop;Yu, Jae-Young;Im, Mee-Ga
    • 대한공업교육학회지
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    • v.42 no.2
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    • pp.108-122
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    • 2017
  • This research paper is to examine James Watt who led the 1st industrial revolution successfully. His great work was called monumental achievement in the human history of civilization. Here, we looked over the Watts' educational environment during his infant, juvenile, and adolescence period and also, his learning attitude about his own field through literature review. The basic infra of soft and hard wares for the industrial revolution through the process of R & D on new developing steam engine resulted from the very industrial revolution and its R & D environment were to be investigated. The useful information and knowledge from this process of the research are able to give an appropriate educational guidance to bring up the development of creativity in schooling systems. And also a lesson from the past could be used to provide the desirable direction for the 4th industrial revolution which is just begun to start now. The main results from this study are as follows; First, Watts' parents positively guided him onto the technology of manual field because they recognized their son was interested in technology field. The parents' attitude stimulated and guided his sons' self-development, had been equal to the aims of education. Second, Watt made a chance of making friendships with professors of Glasgow University. He spontaneously had done self-directed learning for getting knowledge and technology, and thus he became an expert of practical engineer and theorist. Third, the Lunar society, which was jumping over one's social position in their society of the 18th century through new thinking way, leading new ages had been very good R & D social infra for Watt to open and connect new advanced level of science and technology in his age. This society provided a study environment fields for their members to exchange their ideas of scientific curiosity and freely inquiry, technology informations. They had discussed and understood the issues to be occurred in their own fields and accumulated necessary knowledge for problem-solving, respectively. Such as this R & D system environment will be also considered in the modern research group. Fourth, the entrepreneur such as Boulton, who understand technology and grasp its value in future, is needed. The system of 'grue of management' will support the researcher with financial support, which is necessary in R & D. And the researcher like Watt who takes pleasure in technology itself and study eagerly in his field without financial problems, that is, 'grue of technical expert' is essential when leading to success in the industrial revolution.

Retrieval of Hourly Aerosol Optical Depth Using Top-of-Atmosphere Reflectance from GOCI-II and Machine Learning over South Korea (GOCI-II 대기상한 반사도와 기계학습을 이용한 남한 지역 시간별 에어로졸 광학 두께 산출)

  • Seyoung Yang;Hyunyoung Choi;Jungho Im
    • Korean Journal of Remote Sensing
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    • v.39 no.5_3
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    • pp.933-948
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    • 2023
  • Atmospheric aerosols not only have adverse effects on human health but also exert direct and indirect impacts on the climate system. Consequently, it is imperative to comprehend the characteristics and spatiotemporal distribution of aerosols. Numerous research endeavors have been undertaken to monitor aerosols, predominantly through the retrieval of aerosol optical depth (AOD) via satellite-based observations. Nonetheless, this approach primarily relies on a look-up table-based inversion algorithm, characterized by computationally intensive operations and associated uncertainties. In this study, a novel high-resolution AOD direct retrieval algorithm, leveraging machine learning, was developed using top-of-atmosphere reflectance data derived from the Geostationary Ocean Color Imager-II (GOCI-II), in conjunction with their differences from the past 30-day minimum reflectance, and meteorological variables from numerical models. The Light Gradient Boosting Machine (LGBM) technique was harnessed, and the resultant estimates underwent rigorous validation encompassing random, temporal, and spatial N-fold cross-validation (CV) using ground-based observation data from Aerosol Robotic Network (AERONET) AOD. The three CV results consistently demonstrated robust performance, yielding R2=0.70-0.80, RMSE=0.08-0.09, and within the expected error (EE) of 75.2-85.1%. The Shapley Additive exPlanations(SHAP) analysis confirmed the substantial influence of reflectance-related variables on AOD estimation. A comprehensive examination of the spatiotemporal distribution of AOD in Seoul and Ulsan revealed that the developed LGBM model yielded results that are in close concordance with AERONET AOD over time, thereby confirming its suitability for AOD retrieval at high spatiotemporal resolution (i.e., hourly, 250 m). Furthermore, upon comparing data coverage, it was ascertained that the LGBM model enhanced data retrieval frequency by approximately 8.8% in comparison to the GOCI-II L2 AOD products, ameliorating issues associated with excessive masking over very illuminated surfaces that are often encountered in physics-based AOD retrieval processes.

Study on Preparation of High Purity Lithium Hydroxide Powder with 2-step Precipitation Process Using Lithium Carbonate Recovered from Waste LIB Battery (폐리튬이차전지에서 회수한 탄산리튬으로부터 2-step 침전공정을 이용한 고순도 수산화리튬 분말 제조 연구)

  • Joo, Soyeong;Kang, Yubin;Shim, Hyun-Woo;Byun, Suk-Hyun;Kim, Yong Hwan;Lee, Chan-Gi;Kim, Dae-Guen
    • Resources Recycling
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    • v.28 no.5
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    • pp.60-67
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    • 2019
  • A valuable metal recovery from waste resources such as spent rechargeable secondary batteries is of critical issues because of a sharp increase in the amount of waste resources. In this context, it is necessary to research not only recycling waste lithium-ion batteries (LIBs), but also reusing valuable metals (e.g., Li, Co, Ni, Mn etc.) recovered from waste LIBs. In particular, the lithium hydroxide ($LiOH{\cdot}xH_2O$), which is of precursors that can be prepared by the recovery of Li in waste LIBs, can be reused as a catalyst, a carbon dioxide absorbent, and again as a precursor for cathode materials of LIB. However, most studies of recycling the waste LIBs have been focused on the preparation of lithium carbonate with a recovery of Li. Herein, we show the preparation of high purity lithium hydroxide powder along with the precipitation process, and the systematic study to find an optimum condition is also carried out. The lithium carbonate, which is recovered from waste LIBs, was used as starting materials for synthesis of lithium hydroxide. The optimum precipitation conditions for the preparation of LiOH were found as follows: based on stirring, reaction temperature $90^{\circ}C$, reaction time 3 hr, precursor ratio 1:1. To synthesize uniform and high purity lithium hydroxide, 2-step precipitation process was additionally performed, and consequently, high purity $LiOH{\cdot}xH_2O$ powder was obtained.

Experimental and Numerical Analysis of Package and Solder Ball Crack Reliability using Solid Epoxy Material (Solid Epoxy를 이용한 패키지 및 솔더 크랙 신뢰성 확보를 위한 실험 및 수치해석 연구)

  • Cho, Youngmin;Choa, Sung-Hoon
    • Journal of the Microelectronics and Packaging Society
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    • v.27 no.1
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    • pp.55-65
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    • 2020
  • The use of underfill materials in semiconductor packages is not only important for stress relieving of the package, but also for improving the reliability of the package during shock and vibration. However, in recent years, as the size of the package becomes larger and very thin, the use of the underfill shows adverse effects and rather deteriorates the reliability of the package. To resolve these issues, we developed the package using a solid epoxy material to improve the reliability of the package as a substitute for underfill material. The developed solid epoxy was applied to the package of the application processor in smart phone, and the reliability of the package was evaluated using thermal cycling reliability tests and numerical analysis. In order to find the optimal solid epoxy material and process conditions for improving the reliability, the effects of various factors on the reliability, such as the application number of solid epoxy, type of PCB pad, and different solid epoxy materials, were investigated. The reliability test results indicated that the package with solid epoxy exhibited higher reliability than that without solid epoxy. The application of solid epoxy at six locations showed higher reliability than that of solid epoxy at four locations indicating that the solid epoxy plays a role in relieving stress of the package, thereby improving the reliability of the package. For the different types of PCB pad, NSMD (non-solder mask defined) pad showed higher reliability than the SMD (solder mask defined) pad. This is because the application of the NSMD pad is more advantageous in terms of thermomechanical stress reliability because the solderpad bond area is larger. In addition, for the different solid epoxy materials with different thermal expansion coefficients, the reliability was more improved when solid epoxy having lower thermal expansion coefficient was used.

The Economic Cost of the Fair Online Platform Intermediary Transactions Act: A Comparative Case Study (디지털 플랫폼 규제의 경제적 비용: '온라인 플랫폼 공정화법(안)' 사례 연구)

  • Ahn, Yongkil;Kim, Yonghwan;Song, Myungjin
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.17 no.5
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    • pp.237-250
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    • 2022
  • On September 28, 2020, the Korea Fair Trade Commission introduced a proposed bill entitled the "Fair Online Platform Intermediary Transactions Act." We quantify the impact of this proposed act on Naver, Korea's major digital platform. Finding a proper control unit is not an easy task in social science studies. We overcome this caveat by constructing a synthetic version of Naver using Abadie & Gardeazabal's (2003) synthetic control method. It appears that the economic cost of the proposed act is not negligible at all. Naver's opportunity loss amounted to 16.18% of its market capitalization (approximately 8.5 trillion won in comparison with its pre-regulation market capitalization). Any regulation-based approaches to resolving digital platform issues have both promises and pitfalls. The results highlight that regulatory bodies should carefully gauge the impact of such regulations, as we have seen with Naver's case.

Survey of the Status of Conutry-of-origin Lables and Hygine on the Meat Markets of 4 Regions in Korea (4개 권역 축산물 판매업소의 원산지 표시실태 및 위생상태 표본조사)

  • Nam, Bo-Ra;Nam, Jung-Oak;Park, Jung-Min;Lee, Ra-Mi;Gu, Hyo-Jung;Kim, Myung-Hee;Chang, Un-Jae;Suh, Hyung-Joo;Kim, Jin-Man
    • Food Science of Animal Resources
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    • v.27 no.1
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    • pp.122-126
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    • 2007
  • Expenditure on meat and meat products has been increased in Korea due to the increase of income and the change of diet. From raising farm animals to eating the meat, various hazardous elements can make their ways into the meat and meat products. Recently the issues on food safety and hygiene are drawing a lot of attention, and the current system for managing the safety of foods is still needed to be improved. This survey was aimed to monitor the current situation of country-of-origin labels and hygiene for the meat markets at 4 regions Korea. The survey was performed by collecting samples from whole- sale and retail stores in the nation, which were selling beef. The markets were divided into groups as to territory and the size of the market (Large size, Medium size, and Small size). In terms of size distribution, small butcher shops occupied the highest percentage. On the itemized suitability test of unpacked and packed beef, all the market of 4 regions showed good agreements. However, such labels indicating the methods of cooking and storage were not properly posted on the products. Especially for Ho-nam region, corrections are needed. The results of monitoring sanitation conditions for the butcher shops at 4 regions in Korea showed relatively low suitability. Especially, there were serious lack of knowledge about wearing the sanitation clothing, caps, and shoes. The problem with food safety is so complicated that producer, consumer, food manufacturer, the press, the government, and scholar should solve altogether. It is necessary to educate farmers, food handlers, consumers, etc. and provide them with an accurate information and knowledge.