• Title/Summary/Keyword: Structural Problems

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Adhesion Characteristics and the High Pressure Resistance of Biofilm Bacteria in Seawater Reverse Osmosis Desalination Process (역삼투 해수담수화 공정 내 바이오필름 형성 미생물의 부착 및 고압내성 특성)

  • Jung, Ji-Yeon;Lee, Jin-Wook;Kim, Sung-Youn;Kim, In-S.
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.1
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    • pp.51-57
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    • 2009
  • Biofouling in seawater reverse osmosis (SWRO) desalination process causes many problems such as flux decline, biodegradation of membrane, increased cleaning time, and increased energy consumption and operational cost. Therefore biofouling is considered as the most critical problem in system operation. To control biofouling in early stage, detection of the most problematic bacteria causing biofouling is required. In this study, six model bacteria were chosen; Bacillus sp., Flavobacterium sp., Mycobacterium sp., Pseudomonas aeruginosa, Pseudomonas fluorescens, and Rhodobacter sp. based on report in the literature and phylogenetic analysis of seawater intake and fouled RO membrane. The adhesion to RO membrane, the high pressure resistance, and the hydrophobicity of the six model bacteria were examined to find out their fouling potential. Rhodobacter sp. and Mycobacterium sp. were found to attach very well to RO membrane surface compared to others used in this study. The test of hydrophobicity revealed that the bacteria which have high hydrophobicity or similar contact angle with RO membrane ($63^{\circ}$ of contact angle) easily attached to RO membrane surface. P. aeruginosa which is highly hydrophilic ($23.07^{\circ}$ of contact angle) showed the least adhesion characteristic among six model bacteria. After applying a pressure of 800 psi to the sample, Rhodobacter sp. was found to show the highest reduction rate; with 59-73% of the cells removed from the membrane under pressure. P. fluorescens on the other hand analyzed as the most pressure resistant bacteria among six model bacteria. The difference between reduction rates using direct counting and plate counting indicates that the viability of each model bacteria was affected significantly from the high pressure. Most cells subjected to high pressure were unable to form colonies even thought they maintained their structural integrity.

A Comparative Study on Hydraulic Jump and Specific Energy Losses at Downstream According to the Weir Discharge Types (보 유출형태에 따른 하류부 도수 및 비에너지 손실에 관한 비교 연구)

  • Park, Hyo-Seon;Yoon, Geun-Ho;Koo, Bon-Jin;Choi, Gye-Woon
    • Journal of Wetlands Research
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    • v.15 no.1
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    • pp.149-157
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    • 2013
  • The weirs built so far are mainly overflow type weirs overflowing to the upstream. Main advantages of overflow type weirs are, effective water resources management and easy design, construction and maintenance due to many accumulated studies. However, due to the special feature of the overflow type weir where water overflows through the upstream of the weir, the silt coming from the upstream is not discharged to the downstream of the weir. This increases the river bed and reduces the reservoir capacity, and as a result, the weir loses its function. A underflow type weir with a water gate has been implemented in order to solve such sediment deposit and weir maintenance problems. However due to the design problem of recently constructed underflow type weirs, the river bed of the downstream of a weir has been scoured. And this leds to a structural problem. In this study, the flow characteristics of overflow type weirs and underflow type weir, hydraulic jump length analysis depending on change of water depth and the amount of specific energy loss generated per unit length depending on a weir type have been compared and analyzed, for the effective design and management of the weirs. The experiment results show that, when identical upstream conditions of underflow type weir and an overflow type weir were maintained, the hydraulic jump length was up to twice longer with Fr(Froude number) 3.5 of the hydraulic jump length at the underflow type weir, and the hydraulic jump length gradually decreased as the downstream water depth increased. The comparative analysis result of the amount of specific energy loss generated per unit length showed that the amount of energy loss per unit length was twice higher for an overlfow type weir than a underflow type weir. Therefore, in case of a underflow type facility, an additional energy reduction facility is determined to be necessary for safety of water construction structures.

A Study on the Restructuration of Norm System in the Field of ICT for the Smart Media (Smart미디어시대 정보통신·미디어(ICT) 분야 규범체계의 재구조화에 관한 연구)

  • Ji, Seong-Woo
    • Journal of Legislation Research
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    • no.44
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    • pp.33-62
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    • 2013
  • In this paper, the consolidation of ICT basic legislation and ICT special legislation concerning "Ministry of Science, ICT and Future Planning" and "Korea Communications Commission" which came on the back of governmental reorganization in recent years is discussed in the theoretical and practical aspect. Development of "data communication technology" innovatively changed the method of livelihood of mankind, the emergence of network under global dimension provided financial social benefit and posed a challenge and a threat at the same time. Form digital revolution human kind can expect to receive many important blessings. Nevertheless, there are many advantages of development of technology by digital revolution, cyberspace like online media, internet etc. has realistically many problems that must be solved. To maximum positive aspects like the expansion of freedom of expression and creating plan of economy by the advance of transmission technology is needed. And to minimize side effects of informatization is required more. The First, Special Act on ICT has an adaptation in normative standardization to be fit in media convergence beyond convergence of broadcasting and telecommunications. Henceforth, there must be established a legal basis for the achievement of protection of economic evolution and freedom of speech in digital media, information, communication technology and content development. The second, the government action is to accomplish economic development and freedom of information in structural aspect of norm. Therefore minimizing normative problem by reorganization of organization remains clearly unresolved in politics. The third, Special Act on ICT must be basic law covering info-communications field, pay telecommunication and media contents field. The forth, from a technical point of view, net neutrality, conflict of interest for digital content and so on can be fixed easily. Special Act on ICT must not only pursuit of development of industry. Special Act on ICT and pursuit of enhancing quality of life of people and preparing program to promote democratization. From now on, we need to make powerful nation of information& communications technology and in information human rights protection field got to be one step ahead of others with reference to appear all the various aspects must be brought together in the discussion of legislation process of Special Act on ICT.

Mythologies of Design Thinking: Based on Roland Barthes's Mythologies (디자인 씽킹의 신화성 - 롤랑바르트 기호의 신화론을 배경으로)

  • Kim, Kyung-Won
    • 기호학연구
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    • no.57
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    • pp.7-26
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    • 2018
  • The purpose of this paper is to interpret the discourse on design thinking through the perspective of Roland Barthes' Mythologies. To this end, this paper will explore the mythologization process of design thinking using the methodological framework of Barthes, which structurally interprets the connotations produced using semiosis. Design thinking originally refers to a method which is used in the process of planning ideas about designs in order to create the final products for professional designs. However, design thinking has recently attracted more interest from the public because it has become known as a tool for solving various problems which exist outside of the field of design, such as social issues, management, and marketing strategies. Barthes points out that myths are used as a tool to deliver ideologies. He also emphasizes the importance of 'structural thinking'. It interprets the inherent connotative meanings more than the denotative meanings, which are explicitly shown. One of the most powerful ideologies which our society embraces today is creativity. Design thinking realizes the manifestation of creativity through a schematized process. This can be explained by considering design thinking as an icon that is specifically turned into a figuration to realize its objectness, in which a discourse for solving issues and social codes meet together and form a mythology. The mythologies that Barthes cites in his book refer to mythical values created by the cultural codes which humans have produced in our modern and contemporary age. The symbolic value of design thinking has become more important than the signifier which design thinking itself presents. This means that design thinking has become a sign that has mythical properties. In other words, the ideology of creativity embodied by design thinking has attained a mythological status, as it produces a new cultural code through innovation. The process of interpreting a phenomenon using the perspective of semiotics is an important tool that allows us to examine the concept of an object and its surroundings thoroughly. This paper attempts to expand the external scope of critical analysis about social phenomena by using the signs which continuously reveal themselves in common ideologies, such as design thinking, which has been gaining more popularity recently.

Is Fertility Rate Proportional to the Quality of Life? An Exploratory Analysis of the Relationship between Better Life Index (BLI) and Fertility Rate in OECD Countries (출산율은 삶의 질과 비례하는가? OECD 국가의 삶의 질 요인과 출산율의 관계에 관한 추이분석)

  • Kim, KyungHee;Ryu, SeoungHo;Chung, HeeTae;Gim, HyeYeong;Park, HeongJoon
    • International Area Studies Review
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    • v.22 no.1
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    • pp.215-235
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    • 2018
  • Policy concerns related to raising fertility rates are not only common interests among the OECD countries, but they are also issues of great concern to South Korea whose fertility rate is the lowest in the world. The fertility rate in South Korea continues to decline, even though most of the national budget has been spent on measures to address this and many studies have been conducted on the increase in the fertility rates. In this regard, this study aims to verify the effectiveness of the detailed factors affecting the fertility rate that have been discussed in the previous studies on fertility rates, and to investigate the overall trend toward enhancing the quality of life and increasing the fertility rate through macroscopic and structural studies under the recognition of problems related to the policy approaches through the case studies of the European countries. Toward this end, this study investigated if a high quality of life in advanced countries contributes to the increase in the fertility rate, which country serves as a state model that has a high quality of life and a high fertility rate, and what kind of social and policy environment does the country have with regard to childbirth. The analysis of the OECD Better Life Index (BLI) and CIA fertility rate data showed that the countries whose people enjoy a high quality of life do not necessarily have high fertility rates. In addition, under the recognition that a country with a high quality of life and a high birth rate serves as a state model that South Korea should aim for, the social characteristics of Iceland, Ireland, and New Zealand, which turned out to have both a high quality of life and a high fertility rate, were compared with those of Germany, which showed a high quality of life but a low fertility rate. According to the comparison results, the three countries that were mentioned showed higher awareness of gender equality; therefore, the gender wage gap was small. It was also confirmed that the governments of these countries support various policies that promote both parents sharing the care of their children. In Germany, on the other hand, the gender wage gap was large and the fertility rate was low. In a related move, however, the German government has made active efforts to a paradigm shift toward gender equality. The fertility rate increases when the synergy lies in the relationship between parents and children; therefore, awareness about gender equality should be firmly established both at home and in the labor market. For this reason, the government is required to provide support for the childbirth and rearing environment through appropriate family policies, and exert greater efforts to enhance the effectiveness of the relevant systems rather than simply promoting a system construction. Furthermore, it is necessary to help people in making their own childbearing decisions during the process of creating a better society by changing the national goal from 'raising the fertility rate' to 'creating a healthy society made of happy families'

The Determinants of Consumption Characteristics and Patterns of Elderly Households (고령자 가구의 소비특성 및 소비패턴 결정요인)

  • Kim, Jinhun
    • 한국노년학
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    • v.36 no.3
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    • pp.905-926
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    • 2016
  • Although the concept of the elderly varies depending on scholars and laws, as consumption expenditure is deeply associated with income due to the nature of this study, 55 years old was set as the low limit standard for the elderly according to Prohibition of Discrimination on Age in Employment and Employment Promotion for the Aged Act and the elderly households were limited to single-elderly person household and an elderly couple family household for this study. It is considered consumption characteristics as a significant analysis subject in terms of social welfare because it could be understood as an expressed need which was a reflection of desire. Therefore, the present study aimed to investigate the consumption characteristics of the elderly households by stereotyping the consumption pattern of the elderly households, and find the determining factors for consumption patterns and thus contribute to the establishment of related policies through the expressed needs of the elderly households. K-means of cluster analysis was performed by putting the consumption expenditure of the elderly households to investigate inherent structural type of consumption pattern of the elderly households, which were the investigation subjects. As a result, four groups were stereotyped and named as below: 'health care-centered type', 'saving-centered type', 'livelihood-centered type', and 'food expenses-centered type' Binary Logistic Regression analysis was used to identify the factors that influence the decision of consumption pattern of the elderly households. The result of study showed that the elderly households faced all different needs and problems and thus there is a need for various approach plans to solve this situation. In particular, although the elderly have been viewed as economically poor people so far, the study showed that there were also kind of prepared households through saving. Overall, livelihoodcentered type accounted for the highest portion and, as a factor that influenced this, marital state and household income played an important role. Therefore, it is considered that more active efforts to increase the income of the elderly households are needed. In addition, age, owning of house and subjective health state were found to also have significant influence. Through these results of the study, the elderly's own improvement of awareness on health, presentation of overall standard for health state of the elderly, securement of the elderly's access to cultural life, and financial management coordination for improvement of quality of life, development and dissemination of jobs suitable for the elderly, and dissemination of communal life household, which is a cooperation residential type, were presented as institutional task in the conclusion.

International and domestic research trends in longitudinal connectivity evaluations of aquatic ecosystems, and the applicability analysis of fish-based models (수생태계 종적 연결성 평가를 위한 국내외 연구 현황 및 어류기반 종적 연속성 평가모델 적용성 분석)

  • Kim, Ji Yoon;Kim, Jai-Gu;Bae, Dae-Yeul;Kim, Hye-Jin;Kim, Jeong-Eun;Lee, Ho-Seong;Lim, Jun-Young;An, Kwang-Guk
    • Korean Journal of Environmental Biology
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    • v.38 no.4
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    • pp.634-649
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    • 2020
  • Recently, stream longitudinal connectivity has been a topic of investigation due to the frequent disconnections and the impact of aquatic ecosystems caused by the construction of small and medium-sized weirs and various artificial structures (fishways) directly influencing the stream ecosystem health. In this study, the international and domestic research trends of the longitudinal connectivity in aquatic ecosystems were evaluated and the applicability of fish-based longitudinal connectivity models used in developed countries was analyzed. For these purposes, we analyzed the current status of research on longitudinal connectivity and structural problems, fish monitoring methodology, monitoring approaches, longitudinal disconnectivity of fish movement, and biodiversity. In addition, we analyzed the current status and some technical limitations of physical habitat suitability evaluation, ecology-based water flow, eco-hydrological modeling for fish habitat connectivity, and the s/w program development for agent-based model. Numerous references, data, and various reports were examined to identify worldwide longitudinal stream connectivity evaluation models in European and non-European countries. The international approaches to longitudinal connectivity evaluations were categorized into five phases including 1) an approach integrating fish community and artificial structure surveys (two types input variables), 2) field monitoring approaches, 3) a stream geomorphological approach, 4) an artificial structure-based DB analytical approach, and 5) other approaches. the overall evaluation of survey methodologies and applicability for longitudinal stream connectivity suggested that the ICE model (Information sur la Continuite Ecologique) and the ICF model (Index de Connectivitat Fluvial), widely used in European countries, were appropriate for the application of longitudinal connectivity evaluations in Korean streams.

Development and Validation of Classroom Problem Behavior Scale - Elementary School Version(CPBS-E) (초등학생 문제행동선별척도: 교사용(CPBS-E)의 개발과 타당화)

  • Song, Wonyoung;Chang, Eun Jin;Choi, Gayoung;Choi, Jae Gwang;ChoBlair, Kwang-Sun;Won, Sung-Doo;Han, Miryeung
    • Korean Journal of School Psychology
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    • v.16 no.3
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    • pp.433-451
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    • 2019
  • This study aimed to develop and validate the Classroom Problem Behavior Scale - Elementary School Version (CPBS-E) measure which is unique to classroom problem behavior exhibited by Korean elementary school students. The focus was on developing a universal screening instrument designed to identify and provide intervention to students who are at-risk for severe social-emotional and behavioral problems. Items were initially drawn from the literature, interviews with elementary school teachers, common office discipline referral measures used in U.S. elementary schools, penalty point systems used in Korean schools, 'Green Mileage', and the Inventory of Emotional and Behavioral Traits. The content validity of the initially developed items was assessed by six classroom and subject teachers, which resulted in the development of a preliminary scale consisting of 63 two-dimensional items (i.e., Within Classroom Problem Behavior and Outside of Classroom Problem Behavior), each of which consisted of 3 to 4 factors. The Within Classroom Problem Behavior dimension consisted of 4 subscales (not being prepared for class, class disruption, aggression, and withdrawn) and the Outside of Classroom Problem Behavior dimension consisted of 3 subscales (rule-violation, aggression, and withdrawn). The CPBS-E was pilot tested on a sample of 154 elementary school students, which resulted in reducing the scale to 23 items. Following the scale revision, the CPBS-E was validated on a sample population of 209 elementary school students. The validation results indicated that the two-dimensional CPBS-E scale of classroom problem behavior was a reliable and valid measure. The test-retest reliability was stable at above .80 in most of the subscales. The CPBS-E measure demonstrated high internal consistency of .76-.94. In examining the criterion validity, the scale's correlation with the Teacher Observation of Classroom Adaptation-Checklist (TOCA-C) was high and the aggression and withdrawn subscales of the CPBS-E demonstrated high correlations with externalization and internalization, respectively, of the Child Behavior Checklist - Teacher Report Form CBCL-TRF). In addition, the factor structure of the CPBS-E scale was examined using the structural equation model and found to be acceptable. The results are discussed in relation to implications, contributions to the field, and limitations.

Does Brand Experience Affect Consumer's Emotional Attachments? (브랜드의 총체적 체험이 소비자-브랜드의 정서적 유대관계에 미치는 영향)

  • Lee, Jieun;Jeon, Jooeon;Yoon, Jaeyoung
    • Asia Marketing Journal
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    • v.12 no.2
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    • pp.53-81
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    • 2010
  • Brand experience has received much attention from considerable marketing research. When consumers consume and use brands, they are exposed to various specific brand-related stimuli. These brand-related stimuli include brand identity and brand communications(e.g., colors, shapes, designs, slogans, mascots, brand characters) components. Brakus, Schmitt, and Zarantonello(2009) conceptualized brand experience as subjective and internal consumer responses evoked by brand-related stimuli. They demonstrated that brand experience can be broken down into four dimensions(sensory, affective, intellectual, and behavioral). Because experiences result from stimulations and lead to pleasurable outcomes, we expect consumers to want to repeat theses experiences. That is, brand experiences, stored in consumer memory, should affect brand loyalty. Consumers with positive experiences should be more likely to buy a brand again and less likely to buy an alternative brand(Fournier 1998; Oliver 1997). Brand attachment, one of dimensions of the consumer-brand relationship, is defined as an emotional bond to the specific brand(Thomson, MacInnis, and Park 2005). Brand attachment is target-specific bond between the consumer and the specific brand. Thus, strong attachment is attended by a rich set of schema that link the brand to the consumer. Previous researches propose that brand attachments should affect consumers' commitment to the brand. Brand experience differs from affective construct such as brand attachment. Brand attachment is based on interaction between a consumer and the brand. In contrast, brand experience occurs whenever there is a direct and indirect interaction with the brand. Furthermore, brand experience is not an emotional relationship concept. Brakus et al.(2009) suggest that brand experience may result in brand attachment. This study aims to distinguish brand experience dimensions and investigate the effects of brand experience on brand attachment and brand commitment. We test research problems with data from 265 customers having brand experiences in various product categories by using multiple regression and structural equation model. The empirical results can be summarized as follows. First, the paths from affective, behavior, and intellectual experience to the brand attachment were found to be positively significant whereas the effect of sensory experience to brand attachment was not supported. In the consumer literature, sensory experiences for consumers are often equated with aesthetic pleasure. Over time, these pleasure experiences can affect consumer satisfaction. However, sensory pleasures are not linked to attachment such as consumers' strong emotional bond(i.e., hot affect). These empirical results confirms the results of previous studies. Second, brand attachment including passion and connection influences brand commitment positively but affection does not influence brand commitment. In marketing context, consumers with brand attachment have intention to have a willingness to stay with the relationship. The results also imply that consumers' emotional attachment is characterized by a set of brand experience dimensions and consumers who are emotionally attached to the brand are committed. The findings of this research contribute to develop differences between brand experience and brand attachment and to provide practical implications on the brand experience management. Recently, many brand managers have focused on short-term view. According to this study, we suggest that effective brand experience management requires taking a long-term view of marketing decisions.

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A Study on the Development of Ultra-precision Small Angle Spindle for Curved Processing of Special Shape Pocket in the Fourth Industrial Revolution of Machine Tools (공작기계의 4차 산업혁명에서 특수한 형상 포켓 곡면가공을 위한 초정밀 소형 앵글 스핀들 개발에 관한 연구)

  • Lee Ji Woong
    • Journal of Practical Engineering Education
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    • v.15 no.1
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    • pp.119-126
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    • 2023
  • Today, in order to improve fuel efficiency and dynamic behavior of automobiles, an era of light weight and simplification of automobile parts is being formed. In order to simplify and design and manufacture the shape of the product, various components are integrated. For example, in order to commercialize three products into one product, product processing is occurring to a very narrow area. In the case of existing parts, precision die casting or casting production is used for processing convenience, and the multi-piece method requires a lot of processes and reduces the precision and strength of the parts. It is very advantageous to manufacture integrally to simplify the processing air and secure the strength of the parts, but if a deep and narrow pocket part needs to be processed, it cannot be processed with the equipment's own spindle. To solve a problem, research on cutting processing is being actively conducted, and multi-axis composite processing technology not only solves this problem. It has many advantages, such as being able to cut into composite shapes that have been difficult to flexibly cut through various processes with one machine tool so far. However, the reality is that expensive equipment increases manufacturing costs and lacks engineers who can operate the machine. In the five-axis cutting processing machine, when producing products with deep and narrow sections, the cycle time increases in product production due to the indirectness of tools, and many problems occur in processing. Therefore, dedicated machine tools and multi-axis composite machines should be used. Alternatively, an angle spindle may be used as a special tool capable of multi-axis composite machining of five or more axes in a three-axis machining center. Various and continuous studies are needed in areas such as processing vibration absorption, low heat generation and operational stability, excellent dimensional stability, and strength securing by using the angle spindle.