소석회-광물찌꺼기 고형화의 초기 수화에 미치는 황산염의 영향

이현철,민경원,유환근,Lee, Hyun-Cheol,Min, Kyoung-Won,Yoo, Hwan-Geun 대한자원환경지질학회 2013 자원환경지질 Vol.46 No.6

폐광산의 광물찌꺼기의 고형화처리 시 황산염이 초기 수화에 미치는 영향을 확인하기 위하여 본 연구를 수행하였다. 광물찌꺼기에 소석회를 결합재로 사용하였고, $Na_2SO_4$를 혼합수로 이용하여 9가지 조건의 고화체를 제작하였다. 제작된 고화체를 7일, 14일, 28일 양생 후 압축강도 측정, 중금속 용출시험, XRD 분석을 실시하였다. 증류수를 이용하여 양생을 실시한 고화체는 양생기간이 경과함에 따라 압축강도가 증가하였으며, $Na_2SO_4$를 혼합한 고화체는 양생기간 경과에 따라 압축강도가 감소하였다. $Na_2SO_4$의 농도가 증가할수록 고화체 외부 균열이 확실하게 나타났고, 시간이 경과함에 따라 균열이 내부까지 진행되었다. 고화체의 Cu, Cd, Zn, As 농도는 양생기간 경과에 따라 감소하였고, Pb의 경우 소석회 함량이 10 wt% 이상 혼합될 경우 농도가 증가함을 확인하였다. 균열이 발생된 고화체의 수화 생성물에서 석고와 $MgSO_4$ 피크가 XRD 분석으로 확인되었고, SEM-EDS를 통해 주상의 결정이 Ca, S, O로 구성된 석고임을 확인하였다. 소석회를 이용하여 광물찌꺼기를 고형화시킬 경우 황산염 생성으로 균열이 심하게 발생되므로, 황 함량이 높은 광물찌꺼기의 처리 시에는 이를 보완할 수 있는 대책이 강구되어야 할 것으로 판단된다. Influence of sulfate on the early hydration in the solidification treatment of abandoned mine tailings was characterized. Solidified specimens using hydrated lime as a binder were prepared with various amounts of added $Na_2SO_4$ and different curing days. Unconfined compressive strength measurement, heavy metal leaching test, XRD analysis were performed after 7-, 14- and 28-days curing. According to curing days strength of solidified specimens using only distilled water increased but those with addition of $Na_2SO_4$ decreased. External cracks of specimens developed definitely with increasing $Na_2SO_4$ concentration and curing days. Concentrations of Cu, Cd, Zn, and As in the leached solutions from solidified specimens decreased significantly but Pb was leached readily in cases of hydrated lime dosage more than 10 wt%. Gypsum and $MgSO_4$ were identified in the cracked solidified specimens by XRD analysis, and pillar-shaped crystals of SEM image were identified as gypsum in reference with EDS analysis. Crystallization of sulfate in the process of lime-tailing solidification caused cracking, which should be supplemented for solidification treatment of highly sulfur-contained tailing.

공적 연기금 위탁운용 주식의 의결권 행사 효율화 방안에 관한 연구

이현철 ( Lee Hyun-cheol ) 건국대학교 법학연구소 2017 一鑑法學 Vol.0 No.37

본 연구는 공적 연기금의 국내주식 위탁운용 실태와 의결권 행사 현황을 살펴보고 공적 연기금의 위탁운용 주식의 의결권 행사 효율화 방안을 제시하고 있다. 공적 연기금들의 주식 운용은 채권과 달리 위탁운용 위주로 운용이 이루어지고 있는데, 기금규모가 소규모일수록 그리고 액티브한 투자전략을 지닌 포트폴리오에 속해 있을수록 위탁운용 비중이 높은 것으로 나타났다. 위탁운용되는 국내 주식은 모두 투자일임재산에 속해 있으며, 공적 연기금은 직접운용과 위탁운용 여부와 관계없이 모든 국내 주식에 대해 직접 의결권을 행사하고 있었다. 이는 자본시장법상 투자일임재산에 속해 있는 주식의 의결권 위임이 불건전 영업행위로 금지되어 있기 때문이다. 미국의 경우 투자일임재산에 속한 주식의 의결권 위임을 금지하는 규제가 없는 대신 투자일임업자로 하여금 의결권 행사 기준을 마련하여 적용할 것과 의결권 행사와 관련된 정보를 고객이 조회할 수 있도록 공시할 것을 의무화하고 있다. 일본의 기업연금의 경우에도 투자일임 재산에 속한 주식의 의결권을 모두 위탁운용사에게 위임하고 있으며, 위탁운용사로 하여금 의결권 행사 기준을 기금에 제출하고 의결권 행사와 관련된 정보를 기금관리자에게 보고할 것을 의무로 정하고 있다. 공적 연기금이 위탁운용 중인 주식의 효율적인 의결권 행사 방안으로 다섯 가지를 제시하였다. 첫째, 최소한 전문투자자가 일임한 투자일임재산에 속한 주식에 대해서는 의결권 위임을 허용하고, 투자일임업자로 하여금 의결권 행사 기준을 마련하여 위탁자에게 공지 또는 공시하도록 하는 것이다. 둘째, 투자일임재산에만 위탁운용하고 있는 관행에서 벗어나 기업 지배구조 개선에 적극적인 입장인 집합투자기구를 일부 활용하는 방안이다. 셋째, 위탁운용사 선정 기준에 의결권 행사 기준 및 현황을 포함시키고, 이를 제출하도록 하는 것이다. 넷째, 독립적인 의결권 행사 자문기관을 활용함으로써 위탁운용사와 투자대상회사간의 이해상충의 문제와 정부부처의 각종 정책방향 및 정치적 압력 등으로부터 상대적으로 독립된 의결권 행사가 용이하게끔 하는 것이다. 다섯째, 공적 연기금의 의결권 행사지침을 보다 구체화하는 것이다. This study examined the external management practices of domestic equities by Korean public pension funds and the current status of proxy voting on such equities, proposing remedies for proxy voting on equities externally managed by the public pension funds. Unlike fixed income, equities are mostly managed externally by the public pension funds. It was found that the smaller a fund is and the more active the investment strategy of applicable portfolio is, the more applicable fund relies on external management of equities. All of the externally managed domestic equities are held in discretionary investment assets and the public pension funds exercised voting rights on all such domestic equities, whether they were managed internally or externally. This is because the Capital Market Act prohibits proxy voting on equities held in discretionary investment assets as an unfair trade practice. In the United States, proxy voting on equities held in discretionary investment assets is not prohibited, but discretionary investment managers are obligated to develop and enforce proxy voting standards and publicly disclose information related to proxy voting for customers to access. Corporate pension funds in Japan also delegate voting rights on all equities held in discretionary investment assets to applicable external investment managers, and the external investment managers are obligated to submit proxy voting standards to the pension funds and report information related to proxy voting to the pension fund managers. This study proposed five strategies to enable more efficient proxy voting on equities externally managed by public pension funds: firstly, proxy voting can be permitted on equities held in discretionary investment assets externally managed at least by professional investors and the professional investors required to develop proxy voting standards and publicly notify or disclose such standards to applicable clients; secondly, collective investment schemes actively committed to corporate governance improvement can be utilized in part as opposed to the practice of trusting assets only to discretionary investment managers; thirdly, applicable proxy voting standards and current practices can be included in external asset manager selection criteria, with documents supporting such standards and practices to be submitted in the selection process; fourthly, independent proxy advisory firms can be utilized to enable external investment managers exercising voting rights as proxies to facilitate proxy voting relatively independent of the conflict of interest between external investment manager and invested firms, policy stances of government organizations, political pressure, etc.; and fifthly, proxy voting guidelines issued by public pension funds can be rendered more specific by a notch to bolster up consistency and objectivity of proxy voting practices.

유체 애니메이션과 Smart Fish을 이용한 실감형 가상수족관 구축에 관한 연구

이현철(Hyun Cheol Lee) 한국멀티미디어학회 2009 멀티미디어학회논문지 Vol.12 No.1

색소성 양진 2예

이현철 ( Hyun Cheol Lee ),이숙경 ( Suk Keyong Lee ),이흥렬 ( Heung Ryul Lee ),이원우 ( Won Woo Lee ),김덕하 ( Duck Ha Kim ) 대한피부과학회 1995 대한피부과학회지 Vol.33 No.5

Prurigo pigmentosa is a chror ic pruritic inflammatory dermatosis characterized by erythematous papules in a reticulated pattern that resolve leaving a reticulated, mottled hyperpigmentation and rapidly response to dapsone therapy. Most cases that have been reported are from Japan. We report two cases of prurigo pigmentosa in a 21 year-old female and a 23-year-old female. Histopathologic findings of erythematous papules showed exocytosis, spongiosis, liquefaction degeneration of basal cell layer and perivascular lymphohistiocytic infiltration on the upper dermis. We treated them with dapsone, 100mg daily, which resulted in a remarkable regression of the ery thematous papules and improvenien of pruritus. (Kor J Dermatol 1995;33(5): 945-949)

전신성 홍반성 낭창 환자에서 발생한 다발성 피부섬유종

이현철(Hyun Cheol Lee),황계영(Kae Yong Hwang) 대한피부과학회 1994 대한피부과학회지 Vol.32 No.1

We are reporting a case of multiple dermatofibromas which occuired during the treatment of systemic lupus erythematous with prednisolone for 3 years in a 30-yenr-old woman, All of the 26 lesions were 0.5-2cm sized. and had the same appearanes ad usual dermatofibromas coccurring singly. Histopathologic examination showed typical findings of dermatofibroma which were characterized hy proliferation of fibroblasts intermingled with collagen in irregular arrangement and proliferation of small vessels and endothelial cells. (Kor J Dermatol 1994; 32(1): 193-197)

우수한 기계적 특성과 형상치수 확보를 위한 정밀 압출기술개발

이현철(Lee Hyun-Cheol),이광식(Lee Kwang-Sik),오개희(Oh Kae-Hee),박상우(Park Sang-woo) 한국철도학회 2009 한국철도학회 세미나자료 Vol.2009 No.5

Most advanced countries are researching to apply light weight materials for rolling stock because weight reduction for railway body derives cost-saving, energy-saving, and high-speed. Likewise, current Korea rolling stock field makes arduous efforts of weight-reduction, miniaturization, and high-efficiency to achieve a high-speed railway. Aluminum becomes suitable material for these projects because it is much lighter than steel or stainless. Manufacturing the railway car body by using the Aluminum is increasing because Aluminum is not bringing the corrosion by unique oxidation-passivate. Aluminum extrusion profile for railway body requires a high mechanical property, awn-ate shape dimension, and stable quality because the railway body is composed with many different kinds of extruded profiles. Therefore, it is necessary to research about Aluminum precision-extrusion technology to maintain exit temperature and die load. The goal of this project is applying the Aluminum extrusion profile to next-generation railway car body by developing the Aluminum extrusion profile according to precision-extrusion technology which may maintain isothermal exit temperature.

동적 분기 예측을 지원하는 임베디드 코어 자동 생성 시스템의 설계와 구현

이현철(Hyun-cheol Lee),황선영(Sun-young Hwang) 한국통신학회 2013 韓國通信學會論文誌 Vol.38 No.1B

본 논문은 분기 예측을 지원하는 임베디드 코어 자동 생성 시스템을 제안한다. 제안된 시스템은 동적 분기 예측모듈에 히스토리/분기방향 flag가 추가된 BTAC(Branch Target Address Cache)를 포함하여 타겟 어플리케이션의 수행 속도를 향상 시킬 수 있도록 하였다. 시뮬레이션으로부터 해당 어플리케이션의 분기 정보를 추출하고 이를 토대로 BHT(Branch History Table)와 BTAC의 entry를 결정한다. 제안된 분기 예측의 효율성을 검증하기 위해서 동적 분기 예측 모듈을 포함하는 ARM9TDMI 코어를 SMDL로 기술하고 코어를 생성하였다. 실험 결과는 entry의 수에 따라 면적은 60%까지 증가하였고 어플리케이션의 수행 사이클과 BTAC의 miss rate는 평균 1.7%, 9.6%씩 감소하였다. This thesis proposes an automatic embedded core generator system that supports branch prediction. The proposed system includes a dynamic branch prediction module that enhances execution speed of target applications by inserting history/direction flags into BTAC(Branch Target Address Cache). Entries of BHT(Branch History Table) and BTAC are determined based on branch informations extracted by simulation. To verify the effectiveness of the proposed branch prediction module, ARM9TDMI core including a dynamic branch predictor was described in SMDL and generated. Experimental results show that as the number of entry rises, area increase up to 60% while application execution cycle and BTAC miss rate drop by an average of 1.7% and 9.6%, respectively.

도시형 자기부상열차에 대한 철도안전법과 도시철도안전법의 충돌안전기준 적용의 비교 연구

이현철(Lee Hyun-Cheol),구정서(Koo Jeong-Seo) 한국철도학회 2008 한국철도학회 학술발표대회논문집 Vol.- No.-

This paper studied on the application of Korean Railway Safety Law and Urban Transit Safety Law in Crashworthiness Regulations to the urban maglev vehicle of KIMM. The crashworthiness regulations for urban transit vehicle should be satisfied to the urban maglev vehicles according to crash analysis results using the explicit finite element method. However, according to its numerical results, the crashworthiness regulations of Korean Railway Safety Law were partially satisfied except the coupling and shunting condition. When a commercial urban maglev vehicle is developed in the near future, the crashworthiness regulations of Korean Railway Safety Law should be considered and satisfied during its structural design stage in some details

Bednar씨 종양

이현철(Hyun Cheol Lee),심명석(Myung Suk Sim),서동엽(Dong Youb Suh),박동선(Dong Sun Park),강진국(Jin Kook Kang) 대한외과학회 1990 Annals of Surgical Treatment and Research(ASRT) Vol.38 No.1

성능평가 계층을 가지는 신경망제어기 설계

이현철(Hyun Cheol Lee),조원철(Won Chul Cho),전기준(Gi Joon Jeon) 대한전자공학회 1992 대한전자공학회 학술대회 Vol.1992 No.10

We propose a new control architecture which consists of a PI controller and a neural network(NN) controller connected together in parallel. This architecture is well adapted to a wide range of uncertainties and variations of systems. The NN controller is learned through weights of the emulator which identify the dynamic characteristics of the systems. A performance evaluation level of two NN's decides automatically which controller of the two controllers will be used mainly. The PI controller operates mainly during learning phase of the NN controller whereas a good performance is obtained from the NN controller only, when the NN controller is learned sufficiently.