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Evaluation of Manganese Removal from Acid Mine Drainage by Oxidation and Neutralization Method (산화법과 중화법을 이용한 산성광산배수 내 망간 제거 평가)

  • Kim, Bum-Jun;Ji, Won-Hyun;Ko, Myoung-Soo
    • Economic and Environmental Geology
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    • v.53 no.6
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    • pp.687-694
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    • 2020
  • Two oxidizing agents (KMnO4, H2O2), and one neutralizing agent (NaOH) were applied to evaluate Mn removal in mine drainage. A Mn2+ solution and artificial mine drainage were prepared to identify the Fe2+ influence on Mn2+ removal. The initial concentrations of Mn2+ and Fe2+ were 0.1 mM and 1.0 mM, respectively. The injection amount of oxidizing and neutralizing agents were set to ratios of 0.1, 0.67, 1.0, and 2.0 with respect to the Mn2+ mole concentration. KMnO4 exhibited a higher removal efficiency of Mn2+ than did H2O2 and NaOH, where approximately 90% of Mn2+ was removed by KMnO4. A black MnO2 was precipitated that indicated the oxidation of Mn2+ to Mn4+ after an oxidizing agent was added. In addition, MnO2 (pyrolusite) is a stable precipitate under pH-Eh conditions in the solution. However, relatively low removal ratios (6%) of Mn2+ were observed in the artificial mine drainage that included 1.0 mM of Fe2+. The rapid oxidation tendency of Fe2+ as compared to that of Mn2+ was determined to be the main reason for the low removal ratios of Mn2+. The oxidation of Fe2+ showed a decrease of Fe concentration in solution after injection of the oxidizing and neutralizing agents. In addition, Mn7+ of KMnO4 was reduced to Mn2+ by Fe2+ oxidation. Thus, the concentrations of Mn increased in artificial mine drainage. These results revealed that the oxidation method is more effective than the neutralization method for Mn removal in solution. It should also be mentioned that to achieve the Mn removal in mine drainage, Fe2+ removal must be conducted prior to Mn2+ oxidation.

Development of Digital Transceiver Unit for 5G Optical Repeater (5G 광중계기 구동을 위한 디지털 송수신 유닛 설계)

  • Min, Kyoung-Ok;Lee, Seung-Ho
    • Journal of IKEEE
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    • v.25 no.1
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    • pp.156-167
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    • 2021
  • In this paper, we propose a digital transceiver unit design for in-building of 5G optical repeaters that extends the coverage of 5G mobile communication network services and connects to a stable wireless network in a building. The digital transceiver unit for driving the proposed 5G optical repeater is composed of 4 blocks: a signal processing unit, an RF transceiver unit, an optical input/output unit, and a clock generation unit. The signal processing unit plays an important role, such as a combination of a basic operation of the CPRI interface, a 4-channel antenna signal, and response to external control commands. It also transmits and receives high-quality IQ data through the JESD204B interface. CFR and DPD blocks operate to protect the power amplifier. The RF transmitter/receiver converts the RF signal received from the antenna to AD, is transmitted to the signal processing unit through the JESD204B interface, and DA converts the digital signal transmitted from the signal processing unit to the JESD204B interface and transmits the RF signal to the antenna. The optical input/output unit converts an electric signal into an optical signal and transmits it, and converts the optical signal into an electric signal and receives it. The clock generator suppresses jitter of the synchronous clock supplied from the CPRI interface of the optical input/output unit, and supplies a stable synchronous clock to the signal processing unit and the RF transceiver. Before CPRI connection, a local clock is supplied to operate in a CPRI connection ready state. XCZU9CG-2FFVC900I of Xilinx's MPSoC series was used to evaluate the accuracy of the digital transceiver unit for driving the 5G optical repeater proposed in this paper, and Vivado 2018.3 was used as the design tool. The 5G optical repeater digital transceiver unit proposed in this paper converts the 5G RF signal input to the ADC into digital and transmits it to the JIG through CPRI and outputs the downlink data signal received from the JIG through the CPRI to the DAC. And evaluated the performance. The experimental results showed that flatness, Return Loss, Channel Power, ACLR, EVM, Frequency Error, etc. exceeded the target set value.

Use of mothers' home meal replacement and diet quality of their young children (유아 어머니의 유아식사에서 가정간편식 이용 빈도에 따른 유아 자녀의 식사의 질 평가)

  • Kim, Bo-Yeon;Kim, Mi-Hyun
    • Journal of Nutrition and Health
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    • v.54 no.3
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    • pp.292-304
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    • 2021
  • Purpose: This study investigated the association between the mothers' use of home meal replacement (HMR) in their children's meals and the diet quality of their young children. Methods: Three hundred and thirty-seven mothers with five-year-old kindergartners in Sejong city participated in the survey from June to July 2020. The questionnaire consisted of the status of HMR use in children's meals and questions for assessing the nutrition quotient for preschoolers (NQ-P). The subjects were classified into three groups according to the frequency of HMR use in children's meals: using HMR more than three times a week (high-frequency group; [HG], n = 65), one-two times a week (moderate-frequency group; [MG], n = 145), and less than once a week (low-frequency group; [LG], n = 130). Results: The mothers' mean age was 38.3 years. The average monthly cost of purchasing HMRs was highest at 200,000-300,000 won in HG, 50,000-100,000 won in MG, and less than 50,000 won in LG (p < 0.001). The consumption frequency of processed meats, fast foods, processed beverages, and sweet & fatty snacks was significantly higher in the HG group than the other groups. The mean NQ-P score was 60.5 in HG, 63.0 in MG, and 64.5 in LG, showing a significant difference (p < 0.01). In the sub-score according to the three areas, there were no significant differences in balance and environment among the three groups. In the moderation area, however, the score was 44.1 in HG, 51.3 in MG, and 57.5 in LG Group, showing a significant difference (p < 0.001). Conclusion: The increase in HMR use was related to the decreased diet quality in the overall and moderation areas of children's diet. These results support the importance of nutrition education for mothers, which aims to reduce their children's access and exposure to processed foods, such as HMR.

Study on the Performer's Transference and Mental Borderline in a Performance (공연에서 나타나는 '전이'와 배우의 '심리적 경계'에 관한 연구)

  • Kim, Jong-Gu
    • (The) Research of the performance art and culture
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    • no.25
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    • pp.57-89
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    • 2012
  • The performers preparing for a performance usually experience the process of mental transference, contacting with text (drama) for the first time. It is movement from their everyday life to space in the play, when they try to break the wall between cast and themselves. The transference happens actually at the physical space, such as a dressing room, wing, (place just before appearing at a stage), and a stage (place to contact with audience). Performers keep moving among each psychological and physical space repeatedly, until the performance finishes totally. The transference means moving to each space to another, and the mental borderline means the point of mental change the performers experience during the process of transference. The mental borderline can be guessed to exist through mental aspects the performers feel when they move from each space to another. The most typical example, that shows performer's mental borderline well, is stage fright shown as tension, or anxiety among the variety of aspects. According to a research, the most performers experience that kind of mental aspect just before appearing at a stage. The study on it is already referred by my article.' A Study on Korean Performer's Stage Fright. This study aims at examining the relationship among psychological and physical space the performers experience, mental borderline when transferring and penetrating those spaces, and performer's mental change First, the concept of mental borderline is to be understood totally with preceded research. And the space the performers experience and mental borderline at transference are to be reorganized. Secondly, the area of transference in the process of performance is to be reclassified into physical and mental space. Third, analyzing the actual case of performers experiencing the mental borderline, the diversified use should be searched to make use of mental borderline as a positive element. The psychological symptoms, performers experience in the performance, can have positive consequence beside negative one. The tension occurring at the area of borderline is positive, and it can be the actual borderline for the performers. It will be researched how the performers change at the mental borderline, the state of mind is maintained, and they perform in an overall performance, through the study on the relationship between the transference and the mental borderline. And the stress and concentration caused by stage fright, and shyness will be confirmed, and the positive element of a stage, which is used as various defense mechanism.

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.

Thailand in 2017: The Resurgence of "Sarit Model" and Thai-Style Democracy (2017년 타이: '싸릿모델'의 부활과 타이식 민주주의)

  • PARK, Eun-Hong
    • The Southeast Asian review
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    • v.28 no.2
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    • pp.213-247
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    • 2018
  • Thailand in 2017 the public sentiment has turned against the military government. The four pledges the military declared immediately after the 2014 coup, restoration of democracy, addressing of divisive politics, eradication of corruption, and stimulation of the economy have all failed. In the same year, however, Thai military junta began to recover it's diplomatic relationship with western countries including US and EU owing to promulgation of the new constitution endorsed by King Maha Vajiralongkorn and the lavish funeral of late King Bhumibol Adulyadej which was attended by huge number of condolence delegations from around the world including US Defense Secretary James Mattis. Since the 2014 coup, US has sanctioned the country under military junta led by General Prayuth Chan-o-cha for urging them back to the barracks. EU also joined this sanction measures. US signaled change in it's policy when General Prayuth got the chance to visit US and meet President Donal Trump in 2017. General Prayuth Chan-o-cha's military junta could start to restore it's reputation internationally. Domestically, he used absolute powers based on section 44 of the interim constitution, also guranteed in the new constitution. Oversea and national human rights groups have criticized that the interim constitution for permitting the NCPO, Thai military junta's official name, to carry out policies and actions without any effective oversight or accountability for human rights violations. On 1 December 2017, Thailand marked the one-year anniversary of King Maha Vajiralongkorn's accession to the throne as the country's new monarch, Rama X. In the first year of King Rama X's reign, arrests, prosecutions, and imprisonment under Article 112 of Thailand's Criminal Code (lese-majeste) have continued unabated in Thailand. NCPO has continued to abuse Article 112 to detain alleged violators and curb any form of discussion regarding the monarchy, particularly on social media. In this worsening human rights environment General Prayuth Chan-o-cha enforced continuously campaign like Thai-style democracy- an effort to promote largely autocratic 'Thainess' in such a way that freedom of expression is threatened. It is a resurgence of 'Sarit Model'. In the beginning of 2017 Thai military government raised the slogan of 'opportunity Thailand' in the context of 'Thailand 4.0' project which attempts to transform Thai economy based on industry-driven to innovation-driven for recovering robust growth. To consider freedom and liberty as a source of innovation, 'Thailand 4.0' led by 'Sarit Model' without democracy would be skeptical.

Thought of ChunChu and a practical solution of Song Joon Kil (동춘당 송준길의 춘추정신과 현실 대응)

  • Kim, Moon Joon
    • The Journal of Korean Philosophical History
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    • no.50
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    • pp.37-74
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    • 2016
  • Song Joon Kil(宋浚吉, 1606-1672) intended to establish the subjectivity of people as a "Great Justice". He declared that at that time "Great Justice" was meant to respect 'Ming(明)' and reject 'Ching'(淸). He understood 'Ching' as a country which destroyed the human community and reasoned that if we put Ching's uncivilized behavior out of our mind in favor of the pursuit of present existence and merits, a temporary peace may be got but eternal peace and stability would not be achieved. 'Ming' doesn't refer only to the name of a country, but a country with the capacity to perform 'humanity and justice' with a human culture. On the other hand, he considered 'Ching' to signify the uncivilised country that destroyed or repressed the humanity and peaceful order of the world. He thought the international order can only be maintained under the organization respectful and protective of humanity. He believed a country should act to unify the whole world guaranteeing life and stability. He possessed this cultivated spirit which acted to protect the civilised world from the perils of an uncivilised world. But because of the great famine for a lot of years and the international state(Ming was regressing, and Ching was continuing to make rapid strides) was timely unsuitable to revenge and to wash the shame off. So Song propeled to stabilize the government and to strengthen the national ethics. Song focused on administering the domestic affairs. To him a high priority was a internal affairs, and a low priority was a external affairs[military aggression]. Song considered 'providing for the welfare of the people'(安民) before 'pushing ahead with military aggression'(外攘). And a high priority was 'restoring the people'(養民), a low priority was 'the military affairs'(治兵). Song regarded 'domestic affairs'(內治) as a fundamental affairs. He putted 'to nurse people'(養民) and 'to straighten King's mind'(格君心) first, than 'to buildup military'. His foreign policy was 'respecting Ming' and 'rejecting Ching'. Song was bothered about defining Chosun dynasty's moral obligations to the southern Ming government(1644~46) at Nanjing at that time.

A Study on the Determinants of Blockchain-oriented Supply Chain Management (SCM) Services (블록체인 기반 공급사슬관리 서비스 활용의 결정요인 연구)

  • Kwon, Youngsig;Ahn, Hyunchul
    • Knowledge Management Research
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    • v.22 no.2
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    • pp.119-144
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    • 2021
  • Recently, as competition in the market evolves from the competition among companies to the competition among their supply chains, companies are struggling to enhance their supply chain management (hereinafter SCM). In particular, as blockchain technology with various technical advantages is combined with SCM, a lot of domestic manufacturing and distribution companies are considering the adoption of blockchain-oriented SCM (BOSCM) services today. Thus, it is an important academic topic to examine the factors affecting the use of blockchain-oriented SCM. However, most prior studies on blockchain and SCMs have designed their research models based on Technology Acceptance Model (TAM) or the Unified Theory of Acceptance and Use of Technology (UTAUT), which are suitable for explaining individual's acceptance of information technology rather than companies'. Under this background, this study presents a novel model of blockchain-oriented SCM acceptance model based on the Technology-Organization-Environment (TOE) framework to consider companies as the unit of analysis. In addition, Value-based Adoption Model (VAM) is applied to the research model in order to consider the benefits and the sacrifices caused by a new information system comprehensively. To validate the proposed research model, a survey of 126 companies were collected. Among them, by applying PLS-SEM (Partial Least Squares Structural Equation Modeling) with data of 122 companies, the research model was verified. As a result, 'business innovation', 'tracking and tracing', 'security enhancement' and 'cost' from technology viewpoint are found to significantly affect 'perceived value', which in turn affects 'intention to use blockchain-oriented SCM'. Also, 'organization readiness' is found to affect 'intention to use' with statistical significance. However, it is found that 'complexity' and 'regulation environment' have little impact on 'perceived value' and 'intention to use', respectively. It is expected that the findings of this study contribute to preparing practical and policy alternatives for facilitating blockchain-oriented SCM adoption in Korean firms.

Studies on the Structure and Function of the Subsidiary Baekje Temple Building Attachments - Focusing on the Buyeo Wangheungsa Temple - (백제 사찰 부속건물지의 구조와 기능 - 부여 왕흥사지를 중심으로 -)

  • Lee, Sangil
    • Korean Journal of Heritage: History & Science
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    • v.54 no.1
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    • pp.138-163
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    • 2021
  • The Buyeo Wangheungsa Temple was excavated 15 times by the Buyeo National Research Institute of Cultural Heritage by 2015. In doing this, it was confirmed that the attached buildings were placed in the east and west along with the central Sangharama building. Various building sites were established in the western section of the temple, and various buildings were placed inside, and this pattern was estimated in the eastern section. In this article, the structure and function of the attached buildings of the Wangheungsa Temple were focused on the planar structure and excavated artifacts. The most distinctive feature of the attached buildings of the Wangheungsa Temple is their construction alongside the central Sangharama building. It is different from the building to the Neungsan-ri Temple, which was expanded gradually. The attached buildings in the east and west of the lecture hall are presumed to be living space for monks who used solitary rooms, and the attached buildings in the east and west of the main hall were a combination of public work space used for things such as administration, ceremonies, and reception. Next, looking at the outer space of the central Sangharama, the western section was likely constructed at the same time as the central Sangharama. However, if you look at the building site inside the western section, the function has been changed in two stages. The first stage was a ritual space, and it is evident that the western section has a separate entrance and sidewalk and that the workshop was used as a monastery space in the second stage. Finally, there is a distinct possibility that the eastern part of the complex was an important section. Although this space is presumed to be composed of triple towers and halls, it must be have been approached in various ways and included structures related to the operation of temples, such as the monastery space. From this point on, the overall appearance of Baekje temples can be recovered through access to temple structures in a wide variety of ways, including studies of the attached buildings.

Marginal and internal fit of interim crowns fabricated with 3D printing and milling method (3D 프린팅 및 밀링 방법으로 제작된 임시 보철물 적합도 비교 분석)

  • Son, Young-Tak;Son, KeunBaDa;Lee, Kyu-Bok
    • Journal of Dental Rehabilitation and Applied Science
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    • v.36 no.4
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    • pp.254-261
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    • 2020
  • Purpose: The purpose of this study was to assess the marginal and internal fit of interim crowns fabricated by two different manufacturing method (subtractive manufacturing technology and additive manufacturing technology). Materials and Methods: Forty study models were fabricated with plasters by making an impression of a master model of the maxillary right first molar for ceramic crown. On each study model, interim crowns (n = 40) were fabricated using three types of 3D printers (Meg-printer 2; Megagen, Zenith U; Dentis, and Zenith D; Dentis) and one type milling machine (imes-icore 450i; imes-icore GmbH). The internal of the interim crowns were filled with silicon and fitted to the study model. Internal scan data was obtained using an intraoral scanner. The fit of interim crowns were evaluated in the margin, absolute margin, axial, cusp, and occlusal area by using the superimposition of 3D scan data (Geomagic control X; 3D Systems). The Kruskal-wallis test, Mann-Whitney U test and Bonferroni correction method were used to compare the results among groups (α = 0.05). Results: There was no significant difference in the absolute marginal discrepancy of the temporary crown manufactured by three 3D printers and one milling machine (P = 0.812). There was a significant difference between the milling machine and the 3D printer in the axial and occlusal area (P < 0.001). The temporary crown with the milling machine showed smaller axial gap and higher occlusal gap than 3D printer. Conclusion: Since the marginal fit of the temporary crown produced by three types of 3D printers were all with in clinically acceptable range (< 120 ㎛), it can be sufficiently used for the fabrication of the temporary crown.