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Recovery of Indium from Indium Chloride Solutions by Leaching, Enrichment, and Cementation
( Sungkyu Lee ),( Dongyoon Shin ),( Leeseung Kang ),( Sung-soo Ryu ),( Hyun Seon Hong ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 3RINCs초록집 Vol.2015 No.-
A three-step, batch type recovery method was developed to produce indium powders from dilute indium chloride solutions prepared by dissolving indium tin oxide (ITO) electrodes from waste liquid crystal display (LCD) panels in concentrated hydrochloric acid (HCl) solutions. A 5-L batch process was used with individual experimental parameters for cementation, such as temperature and time, which were varied to optimize their effects on the physicochemical properties and purity of the recovered indium powders and the recovery rate. A validation experiment was performed by preparing indium bearing solutions in a 5-180 min kinetic study of indium cementation with aluminum in aqueous HCl solutions at 65℃. The indium powders obtained from the cementation processes were further characterized using various analytical tools, such as ICP/AES, X-ray diffraction (XRD), and scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDS). Cementation at 60℃ for 10 min resulted in the optimal process efficiency, with a recovery rate and indium purity of 70 and 99.8% respectively.
Sungkyu Lee,Tony C. Garrett,Jong-Ho Lee 글로벌지식마케팅경영학회 2016 Global Marketing Conference Vol.2016 No.7
Our study aims to investigate the mechanisms leading to focal firm’s innovation performance through the coopetitive relationships. Specifically, we argue focal firm’s two capabilities, coopetition capability and NPD capability, play a crucial role as a mediator of interfirm coopetition and its innovation performance. In order to provide new evidence on this subject, we contribute to this stream by developing a conceptual model. We argue that coopetitive behaviors of partners will influence the focal firm’s coopetition capability, which will then influence the focal firm’s NPD capability, although we assume NPD capability will have an impact on coopetition capability as well. We also argue NPD capability will not only lead to new product advantages, NPD process advantages as well, as a result of them, financial performance at the end. This paper reports the development of this model.
Public Health Challenges of Electronic Cigarettes in South Korea
Sungkyu Lee,김희진,윤지은,지선하 대한예방의학회 2011 Journal of Preventive Medicine and Public Health Vol.44 No.6
Electronic cigarettes (e-cigarrettes) were recently introduced and advertised as a smoking cession device in South Korea. As the social norm to quit smoking has gained hold in the country, the number of e-cigarette users is growing rapidly. This phenomenon should be urgently considered, because of the lack of research that has been conducted to examine the safety of e-cigarettes and its efficacy as a smoking cessation aid. This paper raises several public health concerns on e-cigarettes in South Korea. Uncertain regulations of the government on e-cigarettes are contributing to an increase of e-cigarette users and allowing the e-cigarette industry to circumvent existing regulations. The aggressive marketing activity of this industry is also a core factor that is responsible for the rapid increase of e-cigarette use, in particular among the youth. Following the enforcement of tobacco control,some cigarette smokers may be encouraged to purchase e-cigarettes in order to circumvent the regulations, even though the dual use of e-cigarette and cigarette may be more harmful. Until there is clear evidence of the e-cigarette’s safety, it is recommended that the industry’s marketing and promotional activities be banned and closely monitored, and public campaigns be initiated to educate the public regarding e-cigarettes.
COOPETITION CAPABILITY IN NEW PRODUCT DEVLEOPMENT; THE PARADOX
Sungkyu Lee,Tony C. Garrett,Jong-Ho Lee 글로벌지식마케팅경영학회 2018 Global Marketing Conference Vol.2018 No.07
Firms cooperate not only with complementary partners such as their suppliers and customers, but also increasingly with their competitors which can result in a simultaneous pursuit of cooperation and competition – coopetition (Brandenburger and Nalebuff, 2011). Coopetition is a paradox as it involves firms interacting with two contradictory logics – cooperation and competition, which their contradictory, yet interrelated, demands seem logical in isolation, but absurd and irrational when appearing simultaneously (Peng et al., 2017). The extant research on the role of the competitor as an NPD partner also throws conflicting results; positive and negative NPD performance. This variance could be related to the firm’s internal capability to manage the partnership in NPD activities. This research aims to investigate these issues: Part I examines ‘the paradox of coopetition’ by investigating how firm’s experience of coopetitive relationship influence on firm’s coopetition capability. Part II investigates the key antecedents and outcomes of coopetition capability on the competitor partnership for new product development. The findings suggest a balanced-strong coopetition and alliance management capability are useful to build coopetition capability. In turn, coopetition capability has direct and indirect effects on NPD performances.
Sungkyu Jung,Jungwoo Lee IEEE 2012 IEEE transactions on signal processing Vol.60 No.11
<P>This paper analyzes the linear degrees of freedom (LDoF) for <I>K</I>-user <I>M</I> ×<I>N</I> MIMO interference channels with constant channel coefficients. In this correspondence, we interpret the interference alignment problem as a multivariate polynomial system in terms of properness. The properness provides a LDoF upperbound for interference alignment. With this approach, we propose a method to obtain the upperbound for total LDoF achievable by linear interference alignment. The LDoF upperbound for properness condition results have two different cases which depend on the number of users, the number of transmit antennas, and the number of receive antennas. A key contribution of this paper is that it provides a closed-form LDoF upperbound for <I>M</I> ×<I>N</I> MIMO interference channels where the LDoF of each user may be different.</P>
Recovery of Tin from Printed Circuit Boards Disassembled from Waste Liquid Crystal Displays
( Sungkyu Lee ),( Leeseung Kang ),( Myung-hwan Hong ),( Dongyoon Shin ),( Sung-su Cho ),( Hyun Seon Hong ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 3RINCs초록집 Vol.2015 No.-
Waste PCBs (Printed Circuit Boards) from LCDs (Liquid Crystal Displays) contain valuable raw materials, Sn, Cu, and other noble metals. Among these, high purity tin was obtained by electro-winning after appropriate acid leaching of tin. For this, leaching and electro-winning process parameters were optimized for solution stability, dissolution and electrolytic efficiency. Two aqueous procedures were developed and tested for electro-winning at mass-production capable basis: (1) HCl leaching after preliminary HNO<sub>3</sub> dissolution was quite effective in leaching high proportion of Sn as analyzed by ICP (Inductively Coupled Plasma) method. (2) Direct one-step leaching in H<sub>2</sub>SiF<sub>6</sub> + H<sub>2</sub>SO<sub>4</sub> + H<sub>2</sub>O<sub>2</sub> was also tested and the solution was finally selected as electrolytes in electro-winning due to massproduction capability. The most efficient recovery of tin was observed after 7h electro-winning in aqueous H<sub>2</sub>SiF<sub>5</sub> + H<sub>2</sub>SO<sub>4</sub> + H<sub>2</sub>O<sub>2</sub> maintained at 40: 96%-pure tin was obtained with 93.2% recovery rate.
Sungkyu Jang(장성규),Jisun Youm(염지선) 한국정부학회 2019 한국행정논집 Vol.31 No.3
본 논문은 지방정부의 체납세금징수 민간위탁이 지방재정의 효율성을 향상시켜줄 수 있을 것인가에 대한 질문을 하기 위해 미국 카운티 정부를 대상으로 실증적 연구를 실행하였다. 이론적 바탕으로는 공공선택론, tax farming, 대리인 이론 등을 근거한 기존 연구들의 문헌연구를 통해 카운티정부의 체납세금을 민간위탁하는 것이 세금 징수의 효율을 높일 가능성이 있다는 가설을 세웠다. 본 가설을 검증하기 위해 각 1997년과 2002년에 수집된 미국 345개 카운티의 통합 데이터를 바탕으로 합동횡단분석(pooled cross sectional regression)을 실시하였다. 분석 결과에 따르면 한 카운티의 체납세금징수를 민간위탁하는 것은 지방정부 세입(revenue)의 효율성을 저하시키는 것으로 나타났다. 이러한 연구 결과는 지방정부의 체납세금 징수를 민간위탁하는 것이 재정적인 관점에서 효율적이지 않음에도 불구하고 많은 지방정부들이 다양한 공공서비스에 대한 민간위탁을 실시하고 있는 것에 대해 의구심을 제기하고 있다. Is contracting out a county’s delinquent tax collection more efficient than making public employees responsible for it? Based on the public choice theory, existing literature on the history of tax farming, and the theory of agency, we hypothesize that contracting out a county’s delinquent tax collection is likely to increase tax collection efficiency. To test our hypotheses, a pooled cross-sectional analysis was conducted using the merged data of 345 counties in the United States from 1997 and 2002. The empirical results show that outsourcing a county’s delinquent tax collection statistically reduces property tax revenue per dollar of financial management expenditure. The outsourcing also reduces the total tax revenue per dollar of financial management expenditure, but not at a statistically significant level. These findings raise the question of why county governments use private debt collectors even though outsourcing delinquent taxes is not efficient from a financial perspective.