• 한국수소및신에너지학회논문집
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• 제30권4호
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• pp.330-337
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• 2019

Effects of cyclone and freeboard geometry on solid entrainment loss were investigated with two different types of cyclones and bubbling beds in a gas-solid fluidized bed system. The solid entrainment loss was measured by collected fines during continuous solid circulation condition. Bubbling bed which has an expanded freeboard showed less solid entrainment than the bubbling bed which has a straight freeboard. The cyclone which has a wide gas-solid mixture inlet showed less solid entrainment loss than the cyclone which has a narrow gas-solid mixture inlet. Moreover, the cyclone has a wide gas-solid mixture inlet can capture smaller particles.

• 한국수소및신에너지학회논문집
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• 제25권2호
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• pp.122-130
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• 2014

Attrition characteristics of WGS catalysts for pre-combustion $ CO_2$ capture were investigated to check attrition loss of those catalysts, to check change of particle size distribution during attrition tests, and to determine solid circulation direction of WGS catalysts in a SEWGS system. The cumulative attrition losses of two catalysts increased with increasing time. However, attrition loss under humidified condition was lower than that under non-humidified condition case for long-term attrition tests. Between two catalysts, attrition loss of PC-29 catalyst was higher than that of commercial catalyst for long-term attrition tests. However, the commercial catalyst generated much more fines than PC-29 catalyst during attrition. Therefore, we conclude that the PC-29 catalyst is more suitable for fluidized bed operation if we take into account the separation efficiency of cyclone. Based on the results from the tests for the effect of humidity on the attrition loss, we selected solid circulation direction from SEWGS reactor to regeneration reactor because the SEWGS reactor contains more water vapor than regeneration reactor.

• Journal of Preventive Medicine and Public Health
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• 제55권6호
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• pp.586-594
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• 2022

Objectives: This study investigated the effectiveness of the social marketing mix approach in increasing students' knowledge about smoking, promoting positive attitudes toward smoking cessation, and decreasing smoking behavior. Methods: This quantitative research study incorporated a quasi-experimental method with a pretest-posttest non-equivalent group design. Using the purposive sampling technique, 152 smoking students were selected as participants. They were divided into 2 equal groups, with 76 students in the control group and 76 in the intervention group. The data were collected using questionnaires and analyzed with the chi-square test, independent t-test, Wilcoxon signed-rank test, and Mann-Whitney U-test. Results: The social marketing mix intervention was effective in increasing the students' knowledge about smoking (p<0.001), improving their attitude toward smoking cessation (p<0.001), and reducing their smoking behavior (p=0.014). Conclusions: This approach should be implemented by local governments to reduce smoking behavior in the community, especially among teenagers, in addition to instituting a smoking ban and applying fines.

• 한국초전도ㆍ저온공학회논문지
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• 제11권4호
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• pp.8-11
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• 2009

This study introduced wastewater treatment method by High Gradient Magnetic Separation (HGMS). HGMS treatment was high efficient method for various industrial wastewaters. The system is currently research state, but we have surveyed commercialize the technology for industry. In rolling plate process, coolant wastewater was recycled by sedimentation and sand filter system. It needs several large reservoirs and long time to remove suspended solid (SS) like metal fines and iron oxide in hot rolling plate making process. If removing rate of suspended solid in rolling coolant wastewater is improved by using HGMS system, the productivity of working process can be increased and the area of reservoir can be reduced. We manufactured high temperature superconducting HGMS system that had a purpose to treatment of coolant wastewater in rolling plate process. We fabricated the prototypes of magnetic matrix filter consisting of stainless steel 430 mesh, which is a core component in the magnetic separation system, In our basic preliminary experiment using HGMS system, it has been clear that the fine paramagnetic particles in the coolant wastewater obtained from rolling plate process of POSCO can be separated with high efficiency.

• Geomechanics and Engineering
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• 제33권1호
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• pp.113-120
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• 2023

Coastal and offshore structures such as ports and offshore wind farms will often need to be built on fine-grained sediments. Geotechnical properties associated with sediment compressibility are key parameters for marine construction designs especially on soft grounds, which involve clay-mineral dominated fines that can consolidate and settle significantly in response to engineered and environmental loads. We conduct liquid limit tests and 1D consolidation tests with fine-grained soils (silica silt, mica, kaolin and bentonite) and biogenic soils (diatom). The pore fluids for the liquid limit tests include deionized water and a series of brines with NaCl salt concentrations of 0.001 m, 0.01 m, 0.1 m, 0.6 m and 2.0 m, and the pore fluids for the consolidation tests deionized water, 0.01 m, 0.6 m, 2 m. The salt concentrations help the liquid limits of kaolin and bentonite decrease, but those of diatom slightly increase. The silica silt and mica show minimal changes in liquid limit due to salt concentrations. Accordingly, compression indices of soils follow the trend of the liquid limit as the liquid limit determined the initial void ratio of the consolidation test. Diatoms are more likely to be broken than clastic sediments during to loading, and diatom-rich sediment is therefore generally more compressible than clastic-rich sediment.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.23-24
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• 2021

The use of recycled concrete aggregates (RCA) as a substitute for natural aggregates in new concrete produces both economic and environmental advantages. Most of the RCA applications for pavements have been primarily applied to support layers for roads and airfields. This paper summarizes a work completed at the University of Illinois in partnership with the O'Hare Modernization Program to examine the effect of coarse and fine RCA on the concrete's fresh and hardened properties for airfield rigid pavement applications. Ten different RCA concrete mixtures were prepared with the incorporation of different percentages of RCA fines as well as replacement of cement with high volume percentages of supplementary cementitious materials such as Class C fly ash and ground granulated blast furnace slag to improve the workability and long-term properties of RCA concrete. All the mixes on this stage included 100% recycled coarse aggregates and the Two-Stage Mixing Approach was used as a mixing procedure. Based on the results obtained in the research, mixes with high percentages of recycled fine and coarse aggregates could be used for construction of airfield concrete pavements in conjunction with supplementary cementitious materials

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.249-255
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• 2011

Poor safety management in construction management may adversely affect cost, schedule and quality of a project. Heavy fines upon safety offence becomes a burden to the budget; losing working hours as a result of safety incident impacts on the schedule, and compromising quality is always an indirect consequence when workers perform duties in an unsafe site environment. Therefore, promotion of safety management becomes the top priority in any construction manager's agenda. Working safely will benefit construction project and lead to a "real" success. This paper is a case study, based upon "Geller's 10 principles for achieving a total safety culture", reviewing how a Hong Kong leading construction company fosters the safety culture and possesses a pleasant safety record over years. Its safety performance is not only well ahead the local industry, but also ranges top within the Asia Pacific region and comparable to those mature Western industries. The review concluded that safety culture is one of the major components in construction management and collaboration is the essence to realize this positive culture within an organization. Safety management is not merely a "top down" approach, but requires the positive "bottom up" actions from the other end. The successful story of this company can demonstrate the contribution of safety management in construction management.

• 월간경쟁저널
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• 73호
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• pp.2-12
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• 2001

미 법무부의 독점금지국(the Antitrust of the U.S. Department of Justice)은, 지난달 제일제당과 두 일본기업이 미 독점금지법 위반을 인정하는데 동의했다고 발표하였다. 미 법무부 독점금지국은 미국 상거래에 영향을 주는 호전적 카르텔에 있어서는, 연루된 기업의 국적에 상관없이, 또한 그 기업이 미국 역내에 있느냐 역외에 있느냐를 불문하고 자국의 독점금지법을 일괄적으로 적용해 오고 있다. 따라서 이런 기업들은 미국 독점금지법하에서 벌금이나 심지어는 금고형으로부터 자유로울 수가 없는 것이 현실이다. 미 법무부의 독점금지국은 판사의 형 선고 재량권을 현저하게 약화시킨 형 선고에 관한 지침(United States Sentencing Guidelines), 그리고 카르텔 공동협력에 있어 공모에 대한 증거제공 및 공동행위를 신고한 기업에 대해 형량감경제도(Corporate Leniency policy)를 효율적으로 운영함으로써 지난 몇 년간 미국 역외에서 발생한 공동행위에 대해 수많은 형사적 유죄판결을 받아내었다. 지난 수십년간 독점금지국은 가격고정, 입찰담합, 시장할당 그리고 셔먼법에 의해 당연위법으로 인정되는 경쟁자간의 합의에 관련된 기업들과 개인들에 대해 조사하고 형사적으로 소추해왔다. 이 모두는 불합리하게 거래를 제한하는 합의로 독점금지법에 의해 금지되는 행위들이다. 연방법은 현재 셔먼법 위반에 대한 벌칙으로 거래를 제한하는 공모에 합의함으로써 셔먼법을 위반한 기업에게는 최고 1,000만 달러, 개인에게는 최고 35만 달러의 벌금을 부과할 수 있으며 최장 3년간의 징역에 처해 질 수 있다고 규정하고 있다. 그러나 벌금액은 1987년의 형사벌금개선법(The Criminal Fines Improvements Act: 법원이 개인 및 기업에 대한 범죄에 의해 야기된 이익이나 손실의 두 배에 해당하는 금액 중 더 큰 금액을 선택적으로 부과할 수 있다는 규정)에 의해 극적으로 늘어나고 있다. 이 논고에서는 미 법무부 독점금지국이 글로벌 카르텔과의 전쟁을 성공적으로 수행하게 된 과정을 간략하게 검토하고, 그 과정에서 다루어진 중요한 사건 중 두 사례를 선정해서 고찰해 보기로 하겠다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.354-354
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• 2009

We have developed the prototypes of superconducting magnetic separation system with high temperature superconductor wire. This separation filter system consist of magnetized matrix SUS430 wire and acrylic frame. This study introduced rolled steel process coolant wastewater applied superconductor HGMS(High Gradient Magnetic Separation). HGMS treatment have acted high efficient method for various wastewater. We have surveyed superconducting magnetic separation technology and reviewed the status of related industries using applied superconductivity. In our basic preliminary experiment using HGMS, it was made clear that the fine para-magnetic particles in the wastewater obtained from rolling process of steel can be separated with high efficiency. We investigated the ability of magnetic flock formation, which used inorganic materials and polymer coagulants. We had a purpose to remove SS of coolant at steel factory. Maximum coagulation remove rate of SS 98%. Removing ratio of $Fe_3O_4$ fine particles in wastewater showed over than 99% in the wastewater containing magnetic fines after four times of repetition of separation.

• 산업클러스터
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• 제1권1호
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• pp.29-46
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• 2007

이 논문은 우리나라 산업 클러스터 형성여건을 파악하고 정책적 함의를 도출하는데 목적이 있다. 이를 위하여 지역혁신사업 추진 주체들을 대상으로 지역의 클러스터 형성수준을 조사한 설문조사 결과를 활용하였다. 그 결과 수도권과 비수도권, 대도시와 중소도시 간에는 클러스터 형성여건과 발전단계가 상이하다. 집적 등 기반조성기 요인들은 양호하나 형성기 요인들인 전략산업별 연구자, 벤처기업과 대기업 관계, 경영, 금융 및 마케팅 등 기업지원기관 및 분리신설기업 등은 취약한 것으로 나타났다. 따라서 발전된 지역과 저 발전된 지역을 구분하고 지역의 여건과 발전단계에 맞는 다양한 사업을 개발하여 추진할 필요가 있다. 수도권과 지방간의 균형발전이 중요한 현 시점에서 지역혁신사업의 입지는 형평성 보다는 효율성, 분산 보다는 집적, 백화점식 보다는 지역의 특화를 고려하여 선정 추진하는 것이 필요하다. 발전된 지역은 지역내 균형발전 방향, 저 발전된 지역은 지역내 선택과 집중 방향으로 추진할 필요가 있다.