• Title/Summary/Keyword: critical current

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Current Research Trends for Treatment of Microplastics (미세플라스틱 처리를 위한 연구동향)

  • Kim, Seong-Min;Baek, Sang-Ho;Han, Yosep;Davaadorj, Tsogchuluun;Go, Byung-Hun;Jeon, Ho-Seok
    • Resources Recycling
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    • v.29 no.5
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    • pp.15-27
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    • 2020
  • Microplastics are recognized as critical and serious environmental problem in worldwide. Plastics are inexpensive, lightweight, excellent in processability, and various in material-specific properties. Along industrial development, the production and disposal amount of plastics are also rapidly increasing. In particular, abundant plastic wastes are eventually disposed into marine environment with harmful impacts on the ecosystem. Therefore, lots of relevant studies were recently progressed in various fields. However, many studies are being just conducted due to its difficulty in applying a general treatment method for those small particle sizes and their various characteristics. In the meantime, lots of researches are being conducted on applying methods using physical properties such as specific gravity, magnetic, and electrostatic separation, which are beneficiation processes of minerals. However, since it is still in the laboratory stage, the development of larger scale separation technology for efficient treatment is urgent.

A Study of Call Service Mechanism on SIP for Emergency Communication Services (긴급통신서비스 제공을 위한 SIP에서의 호 서비스 메커니즘에 관한 연구)

  • Lee, Kyu-Chul;Lee, Jong-Hyup
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.2
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    • pp.293-300
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    • 2007
  • As the development of the various IP-based services, it is expected that Internet telephony service will gradually replace the traditional PSTN-based telephony service. But there are many issues resolved to spread the Internet telephony service. One of them is to support the emergency services in the Internet telephony. In the case of USA, it has been regulated that 911 services should be supported in the Internet telephony services using VoIP on the similar performance level to PSTN 911 service. According to the regulation, basic VoIP 911 calls should be routed to the general access line of LEA without the location information or the callback number, but the enhanced VoIP 911 calls with the location information and callback number should be routed on the dedicated 911 network and destined to the local 911 distribution center such as PSAP. But, in the current VoIP-based Internet telephony network, the emergency call service has not been handled as one of the special services as well at has a worse performance in comparison to it on PSTN. Moreover, the service has a critical problem that it can not be destined to the nearest PSAP because of the insufficient information about the location information and the call back number. In this paper, we suggest the SIP-based emergency call service mechanism in order to resolve the problems above mentioned. This suggested mechanism is implemented to show its effectiveness and efficiency.

A Classification of Research Types and Trend Analysis of Research Methods in Korean for Academic Purposes (학문 목적 한국어교육의 연구 유형 분류와 연구 방법의 동향 분석)

  • Na, Wonju;Joo, Hyunha;Kim, Youngkyu
    • Journal of Korean language education
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    • v.28 no.1
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    • pp.79-111
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    • 2017
  • This study is a trend analysis study that discusses the current status and directions of research methods of KAP research. The existing trend ana lysis studies dealing with research methods have problems in that the classification criteria of the studies used are rough and different from each other, rendering comparison between studies being difficult, and do not comprehensively cover research methods of diversified KAP research. Therefore, this study examined the research methods of KAP research from a critical point of view and suggested a set of classification criteria and an analysis framework that can be used consistently in classification and analysis of future KAP research methods. Based on the theoretical background of second language studies and applied linguistics, this study revised and supplemented Brown (2015)'s research method types and selected 289 journals and theses/dissertations from 2012 to 2016 and classified them into a new analysis framework. The primary and secondary studies, which are the major categories, were 219 and 70, respectively, so it was confirmed that there were much more primary studies. The primary studies then were subdivided into 128 qualitative research studies, 142 survey research studies, and 23 quantitative research studies, pointing to the trend that survey and qualitative research methods were preferred. In the qualitative research approaches, there were 21 action research studies, which were used the most. In addition, such qualitative research approaches as case studies and narrative inquiries which were difficult to find in the past, have gradually increased, confirming that the diversification of research methods is becoming common. However, there were still many studies that did not explicitly put forward research questions and there were many studies that did not report reliability and effect sizes in quantitative research. Of the 23 quantitative studies, only 50% reported reliability, and only three reported effect sizes. In order to enable systematic reviews (meta-analysis) of quantitative research and expect quality improvement of research in future KAP research, reporting of quantitative research should be done more systematically. This study is meaningful in that a systematic and detailed analysis framework was proposed to classify various research methods in the future and that the problems and directions for improvement of the KAP research methods were discussed through the analysis of the research trend of the KAP studies for the last 5 years.

Technology and Exploitation : Limitation of Capitalist Technological Development (과학기술과 착취 : 자본주도형 기술 개발의 한계)

  • Shin, Eun-hwa
    • Journal of Korean Philosophical Society
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    • v.146
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    • pp.115-135
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    • 2018
  • This article attempts to deal with the problem that science and technology function as a mechanism to oppress and exploit humans rather than to release humans from labor. To explore this subject, it is necessary to consider the difference between the theory of labor value and the theory of 'technology value'. In addition, it is also important to refer to Marx's critical view of the 'capitalist' use of technology. Above all, Marx' concepts of relative surplus value and special surplus value, and his analysis of organic composition of capital are still valid in explaining that development of technology tightens control over workers and intensity of labor, and worsens instability of employment. Reflection of the limitations of capitalist development of technology is also important for realization of its usefulness. Industry 4.0 in Germany therefore deserves to be noticed as a good example because it shows a different way from extreme capitalist exploitation. The model suggests also some points that shouldn't be overlooked, when we try to actualize the tremendous slogan of the current fourth industrial revolution as real innovation and progress in human life. In this matter, the most important point is the possibility of technological development that doesn't oppose workers' interests.

A Study on the Critical Factors of Logistics Service Contracts (물류서비스 계약의 결정요인에 관한 연구)

  • Jung, Kyung-Seon;Kim, Tae-Bok
    • Journal of Korea Port Economic Association
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    • v.25 no.3
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    • pp.93-116
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    • 2009
  • As the popularity of logistics service outsourcing has been continuously growing, one of the most frequently addressed issues is how to estimate the effect of cost reduction for users and profit gains from outsourcing contract for providers. Many manufacturing companies agree that logistics outsourcing helps to reduce their operating costs, but some other companies still do not achieve the cost saving or do not trust logistics service providers, so they keep up in-house logistics operations. On the other hand, logistics service providers have low profitability from domestic business activities since they should meet the requirements for highly customized and diverse services from customers and unstable market situation. This study provided the status report dealing with logistics service contracts in Korea. From the focused group interview with logistics professionals, we found out that service scope, scale and cost structure are the most influential factors affecting logistics service contracts. Also, logistics service providers are more sensitive than users regarding value-added logistics service, contract duration and process. Moreover, this study also proposed the standard clauses for logistics service contract and types of logistics contract applied in current logistics fields. As a result, it is expected that these achievements from this study can be utilized to improve the satisfaction of logistics outsourcing in upgrading service quality and customer service level.

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A Proposal on the Consulting Model for Efficient Construction of Material Handling Automation System : Focused on K Company's Case (물류자동화 시스템의 효율적 구축을 위한 컨설팅 방법론 제안 : K기업의 사례를 중심으로)

  • Ko, J.H.;Cho, J.H.;Oh, H.S.;Shim, S.C.;Ryu, J.H.;Lee, S.J.
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.38 no.4
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    • pp.202-211
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    • 2015
  • Companies build the factory automation system to improve management effectiveness and productivity as prime strategies for sustainable growth. But most companies undergo various trials and errors while carrying out the project without elaborate preparation stage for factory automation. In this study, we tried to verify what factors are critical to effectively building distribution automation system, which is a branch of factory automation system. A consulting model for setting up a Material Handling Automation System by utilizing the Stage-Gate Process, which is product development process was studied. 29 material handling automation projects carried out between the year 1990 to 2013 at K-Company were selected. Interviews with the project managers, operators and maintenance personnels, various records and current status of the projects were used as data for structural equations based on the Milan consulting model and existing researches of factory automation, CIM for material handling automation. Creating effective basis of production, material handling system and energy saving system with expert review, when preparing a material handling automation project, help promote the project planning thus contributing to the performance of the resulting system, which appears though rather weakly in our data. Also the effect of material handling automation can be enhanced through sufficient and effective links to the relevant environments such as production logistics management and automated warehouses. More detailed planning characteristics of project promotion or some time-series data of effective Material Handling Automation System could enhace furthur studies. We propose a consulting model for setting up an efficient material handling automation system.

A Study on the Build of Equipment Predictive Maintenance Solutions Based on On-device Edge Computer

  • Lee, Yong-Hwan;Suh, Jin-Hyung
    • Journal of the Korea Society of Computer and Information
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    • v.25 no.4
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    • pp.165-172
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    • 2020
  • In this paper we propose an uses on-device-based edge computing technology and big data analysis methods through the use of on-device-based edge computing technology and analysis of big data, which are distributed computing paradigms that introduce computations and storage devices where necessary to solve problems such as transmission delays that occur when data is transmitted to central centers and processed in current general smart factories. However, even if edge computing-based technology is applied in practice, the increase in devices on the network edge will result in large amounts of data being transferred to the data center, resulting in the network band reaching its limits, which, despite the improvement of network technology, does not guarantee acceptable transfer speeds and response times, which are critical requirements for many applications. It provides the basis for developing into an AI-based facility prediction conservation analysis tool that can apply deep learning suitable for big data in the future by supporting intelligent facility management that can support productivity growth through research that can be applied to the field of facility preservation and smart factory industry with integrated hardware technology that can accommodate these requirements and factory management and control technology.

Economic Valuation of Green Open Spaces: The Effects of Homeownership and Residential Types (도시녹지의 경제가치 평가: 소유 여부와 주택유형의 영향)

  • Choi, Andy Sungnok;Cho, Seong-Hoon
    • Environmental and Resource Economics Review
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    • v.30 no.3
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    • pp.395-433
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    • 2021
  • This paper aims to examine the effects of homeownership and residential types on the economic values of urban green spaces. Green open spaces as public goods provide positive externalities that are comprised of pecuniary and technological externalities. Seoul, South Korea, is used as a case study using choice experiments, with split-sample online respondents of 1,000. The study results evidenced that the differentiation between the two types of externalities is imperative for equitable provisions and efficient management of various urban open spaces. There is a positively significant and substantial impact of homeownership for apartment dwellers, ceteris paribus, but not for house dwellers. For apartments, the efficiency loss can be reduced by increasing green spaces up to the critical point where the marginal cost is at equilibrium with tenants' marginal values. For non-apartment houses, it is not homeownership but the monthly household income that has a significant impact on the amenity value. In general, public benefits from green spaces are equivalent to 16% to 33% of the current residential prices on average for a view or access. Different residential types do not cause a significant impact on the access values. Residential profiles for green spaces were developed, together with tailor-made policy suggestions.

A Myth-Making of Homogeneous Ethnicity of Koreans: A Case Study of Teaching Religion (단일민족, 그 신화 형성에 관한 일 고찰: 종교 가르치기의 한 사례 연구)

  • Ha, Jeonghyun
    • The Critical Review of Religion and Culture
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    • no.29
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    • pp.101-133
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    • 2016
  • The term 'myth' is modern terminology. It was introduced to the East Asia from late 19th century to early 20th century. Under the rule of Japanese imperialism, some Japanese historians insisted that Dangun(檀君) has no relation with Kochoson(古朝鮮). Some Korean historians have refuted their conjecture. The arguments between Japanese and Korean historians bring about the motives of making the concept of Shinwa(神話) The purpose of this study is to investigate the historical procedures of making myth of Homogeneous Korean as a case study of "teaching religion". For the scholar the historic beginning is to be distinguished from later myths of origins. The scholars, particularly among the historians of China, Japan and Korea take it as the beginning of the history to investigate myths, for the ending parts of narratives are in themselves involved in a social constructs in order to give legitimacy to the story. It is apparent to satisfy for the current social demands of the nation-states building. It is also an act of casting and projecting their national values into the far distant past which is considered to be authentic and authorative. The western term 'myth' had been made up in Japanese historical context in order to build "nation-state concept". In Korea, the myth of homogeneous ethnicity of Koreans had been also reconstructed as modern myth during the late 19th and the early 20th century. We can call it the invention of the tradition accordingly.

A Critical Review of the Geographical Location of Anpyeon-do(Baleum-do) Written in the Nanjung Diary by Admiral Yi (난중일기에 기록된 안편도(발음도)의 지리적 위치에 관한 실증 연구)

  • Ko, Kwang-Soob;Pak, Tae-Yong;Kim, Deug-Bong
    • Journal of Navigation and Port Research
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    • v.42 no.6
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    • pp.469-477
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    • 2018
  • Most of the current administrative names and locations for the names of places in the Nanjung diary have since been confirmed. However, a disagreement ensued among translators or researchers over Anpyeon-do (Baleum-do) islet recorded in Admiral Yi Sun-Shin's diary. Anpyeon-do was first recorded in the diary on October 11, 1597. It is credited to be the location where Yi Sun-shin and Chosun Naval Fleet stayed when sailing along the Southwestern coast of the Korean Peninsula after the battle of Myeongnyang. However, Anpyeon-do's exact geographical location has never been accurately confirmed. To accurately locate the islet, this study compared the direction and position of geographical locations observed in the Anpeon-do site match to actual geographical positions and directions. In addition, the direction and position of the geographical locations observed in the newly explored islands and mountains were evaluated with regard to how they correspond to the actual Anpeon-do. As a result, we concluded that the real location of Anpyeon-do recorded in the Nanjung diary is the Maebong mountain in Anjwa-do.