• Title/Summary/Keyword: 산업순환

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Performance Evaluation of Concrete Bench Flume Using Industrial by Products (산업부산물을 이용한 콘크리트 벤치플룸의 성능평가)

  • Jae-Ho Jung
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.11 no.3
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    • pp.276-281
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    • 2023
  • Water pipes manufactured using existing Portland cement suffer from the problem of rapid deterioration and reduced durability due to the hydration product of cement being vulnerable to acids. Therefore, in this study, water pipes were manufactured using slag and fly ash, which are industrial by-products from various industries, and their characteristics were analyzed. As a result of the experiment, slump in unhardened concrete tended to increase due to the ball bearing action of fly ash, and the amount of air was reduced due to unburned coal, indicating that measures for frost resistance were needed. In addition, the initial strength of the compressive strength was increased through steam curing, and the results were equal to or better than OPC when mixing more than 50 % of slag. The acid resistance results showed that the mass reduction rate was less than 5 %, showing excellent durability performance, and the bending failure load of the water pipe also exceeded the KS standards, so it is judged to be commercializable.

The Patterns of Garic and Onion price Cycle in Korea (마늘.양파의 가격동향(價格動向)과 변동(變動)패턴 분석(分析))

  • Choi, Kyu Seob
    • Current Research on Agriculture and Life Sciences
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    • v.4
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    • pp.141-153
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    • 1986
  • This study intends to document the existing cyclical fluctuations of garic and onion price at farm gate level during the period of 1966-1986 in Korea. The existing patterns of such cyclical fluctuations were estimated systematically by removing the seasonal fluctuation and irregular movement as well as secular trend from the original price through the moving average method. It was found that the cyclical fluctuations of garic and onion prices repeated six and seven times respectively during the same period, also the amplitude coefficient of cyclical fluctuations showed speed up in recent years. It was noticed that the cyclical fluctuations of price in onion was higher than that of in garic.

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Pore Structure and Physical Properties of Heterogeneous Bonding Materials of Recycled Aggregate according to Carbonation Reforming (순환 골재 부착 이질재의 탄산화 개질에 따른 공극구조 및 물리적 특성)

  • Shin, Jin-Hak;Kim, Han-Sic;Chung, Lan;Ha, Jung-Soo
    • Journal of the Korea Concrete Institute
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    • v.28 no.3
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    • pp.341-348
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    • 2016
  • At present, about 40 million tons of concrete is dismantled each year, which accounts for the largest portion of the total amount of construction waste with 60.8%. It is known about 97.5% of it is recycled. However, most of the usage of waste concrete is limited to lower value-added business areas, and considering the increasing amount of waste concrete generated due to the deterioration of structures, the need for converting waste concrete to structural concrete is urgent. Therefore, this study aims at estimating the period for the optimum carbonation reforming to improve the quality of recycled aggregate, by making use of the method of accelerated carbonation reforming of the bonding heterogeneous (cement paste and mortar) for the purpose of converting recycled aggregate to structural concrete. Based on the period appropriate for the heterogeneous thickness and each bonding thickness of recycled aggregate which was drawn from previous studies, the changes in the characteristics and physical properties of pore structure according to progress of accelerated carbonation were analyzed. The result shows that with the progress of carbonation, the pore volume and the percentage of water absorption of the bonding heterogeneous decreased and the density increased, which indicates improvement of the product quality. But after certain age, the tendency was reversed and the product quality deteriorated. Synthesizing the results of previous studies and those of the present study, this study proposed 4 days and 14 days respectively for the period for the optimum carbonation reforming of recycled fine aggregate and recycled coarse aggregate.

A Study on the Effects of Employee Value Proposition and the Importance of Job Rotation on the Subjective Career Success (호텔 종사원의 직원가치와 직무순환 중요도가 경력성공에 미치는 영향 연구)

  • Kwon, Na-Kyung;Kim, Hye-Lin;Lee, In-Jee
    • Culinary science and hospitality research
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    • v.19 no.3
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    • pp.291-304
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    • 2013
  • This study analyzed the effects of Employee Value Proposition (EVP) and the impotance of a job rotation system on the subjective career success. The total 379 samples were surveyed from employees engaging in domestic hotel enterprises located in Seoul using convenient sampling method. The result of this research is as followings. First, EVP has total 5 factors('career development,' 'affiliation,' 'work environment,' 'work content' and 'pay & reward') and job rotation has total 3 factors('individual capacity improvement,' 'procedural justice,' and 'career development'). Second, the results of hypotheses test using a series of multiple regression analysis indicate that EVP factors including 'career development,' 'affiliation,' 'work environment,' and 'work content' influence subjective career success. However, EVP factor of 'pay & reward' does not influence subjective career success. Similarly, EVP factors excluding 'pay & reward' affect a job rotation system. Lastly, a job rotation system positively affects subjective career success. Based on the analysis results, we could draw the importance of the non-financial reward instead of financial reward in the perception of employees' subjective career success. As a research implication, the importance of the creative organization culture was suggested in the conclusion section.

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The Effect of Job Rotation on Motivation and Job Satisfaction - Focused on F&B Employees of First Grade Hotels in Seoul - (직무 순환이 동기 부여 및 직무 만족에 미치는 영향에 관한 연구 - 서울 특1급 호텔 F&B 종사원을 중심으로 -)

  • Kwon, Na-Kyung;Kim, Hye-Lin;Seo, Won-Seok
    • Culinary science and hospitality research
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    • v.16 no.4
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    • pp.163-176
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    • 2010
  • The purpose of this study is to find out the effect of job rotation on employees' motivation and satisfaction. That is, it is the ultimate aim to know why employees want job rotation or why not, whether the rotation has an effect on their motivation, and finally whether the motivation gives direct job satisfaction. As a result of the survey, the efficiency and procedure of job rotation have influence on motivation. The employees also think that regular rotation can help them to find the proper position to meet their aptitude. And motivation also affects employees' achievement, benefits, and relationship with their bosses. Especially, when they feel great achievement and pride in their jobs, their satisfaction appeared to be very high. And when they are paid properly in comparison with their workload, or they learn special knowledge from their bosses, they usually content themselves.

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The Role of Process Systems Engineering for Sustainability in the Chemical Industries (화학공정 산업에서의 지속가능성과 공정시스템 공학)

  • Jang, Namjin;Dan, Seungkyu;Shin, Dongil;Lee, Gibaek;Yoon, En Sup
    • Korean Chemical Engineering Research
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    • v.51 no.2
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    • pp.221-225
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    • 2013
  • Sustainability, in general, means the protection of environmental resources and economic prosperity, with the consideration of the social, economic and environmental effect, as well as human health and the enhancement of life. Profound consideration about sustainability has to handle the overall cycle of feedstock, resource extraction, transportation and production in addition to the environmental effect. Sustainable development of the chemical industries should be carried out complementarily by strengthening the chemical process safety of the industries. In this respect, chemical process safety can be called an opportunity to enhance the compatibility internationally. Changing new paradigm in chemical process safety is formed from the overall life cycle considering basic design of existing systems and production processes. To improve the chemical process safety, the integrated smart system is necessary, comprising various chemical safety database and knowledge base and improved methods of quantitative risk analysis, including management system. This paper discussed the necessity of overall life cycle in chemical process safety and proposed new technology to improve the sustainability. To develop the sustainable industries in process systems engineering, three S, which include Safety, Stability and Security, will have to be combined appropriate.

A Study on AI active noise cancellation for daily noise reduction (AI 스피커를 이용한 생활소음 감소)

  • Lee, Jong-Jae;Song, Youn-Joo;Won, Chae-Young;Kim, Min-ji;Kim, Jeong-Min
    • Annual Conference of KIPS
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    • 2021.11a
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    • pp.1203-1206
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    • 2021
  • 소음은 난청, 스트레스 등의 원인이 된다. 본 연구에서는 ANC(Active Noise Cancellation)을 바탕으로, 기술적인 방법을 통해 소음을 저감 시키는 스피커를 구현하였다. ANC 란 소음 주파수의 위상을 180° 변환하여 주파수와 레벨이 동일한 역 소음을 발생시켜 주변 소음을 저감, 차단하는 기술이다. 현재 시중 제품들에 적용되는 일반적인 ANC 의 경우, 피드백(Feedback) 방식이라는 점과 시간 지연(Time gap)이 발생한다는 한계가 있다. 이를 보완하기 위해 AI 학습으로 소음을 미리 예측하여 시간 지연을 줄이는 방법을 고안했다. 순환 신경망(RNN)의 장기의존성 문제를 해결하는 시계열 예측 딥러닝 알고리즘인 LSTM(Long Short-Term Memory Network) 모델을 사용하였다. 또한, AI 학습 효율을 향상시킬 수 있는 하드웨어 장비들을 활용하였다.

Decomposition of BTEX by Gas-phase Photo Reactor (기상광반응기를 이용한 BTEX의 분해)

  • Lee, Nam-Hui;Lee, Gang;Hwang, Du-Seon;Kim, Se-Gi;Kim, Seon-Jae
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2003.03a
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    • pp.77-77
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    • 2003
  • 산업화에 따라 각종 산업분야에서 유기 용제의 사용이 증가하게 되었고 대기오염, 수질오염 등의 상태가 심각해져가고 있는 실정이다 그러나 다양해진 오염물질을 처리하는 데 있어서 기존의 산화처리방법은 한계에 달하였고 새로운 처리공정으로 최근 고급산화법(AOP : Advanced Oxidation Process)에 대한 연구가 활발하게 진행되고 있다. 이에 본 연구에서는 대기환경 및 인체에 심각한 영향을 주는 VOCs(Voletail Organic compounds)중 BTEX(Benzene, Toluene, Ethylbenzene, Xylene)를 다양한 형태의 광촉매제를 이용하여 기상 광분해한 후 이에 대한 최적의 분해 조건과 분해율을 비교하고자 하였다. 순환식의 자체 제작한 기상광반응장치를 이용하여, CVD법으로 TiO$_2$ 입자를 알루미나 비드위에 코팅한 볼과 같은 방법으로 유리기판위에 코팅한 판상의 광촉매제 그리고 결정성이 각기 다른 루틸상과 아나타제 그리고 아나타제/루틸 혼합상의 TiO$_2$ 분말을 직접 이용하여 VOCs 농도와 종류, 광원의 종류 및 세기를 변화시켜 PID(Photo ionization Detector)방식의 순환식 VOCs 측정기를 이용하여 광분해율을 실시간으로 측정하였다.

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VDT 작업장에서 작업시, 시간별 근피로도의 측정 및 정량화

  • 민기식;한정수;이남식;안재용
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • 1997.05a
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    • pp.133-138
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    • 1997
  • 인간공학 및 생체공학을 근거한 종합적인 연구 모델 제시로, 산업체에 산재해있는 작업 중에 VDT Workstation과 관련된 근로자의 상지에 대한 직업성 누적적 질환의 연구로, 상지의 외상성 누적적 질환을 일으킬 수 있는 ergonomic stressor의 감지, 진단, 및 공학적 control를 이용 직업성 누적적 질환 예방을 궁극적 목적으로 하여, 근무 교대 및 일시적 보직 변경 등 근무 순환의 적절한 인사관리 및 누적적 피로를 극소화 할 수 있는 근무/휴식의 적절한 시간 안배를 제시하며, VDT 주변 환경과 근로자 사이의 적절한 운용에 대한 교육 program을 개발, 또한 휴식 시 stretch exercise (근육의 피로 이완을 목적) 방법 등을 제시하며, 누적적 질환의 조기 증상을 감지하여 업무의 적절한 순환을 통하여 직업성 질환으로서의 발전을 방지하고자 하는 것을 취지로 기초연구를 수행하고자 하였다. (중략)

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남해 특별관리해역의 환경오염 관리모델 연구 - 광양만 중심 연구에서의 현황과 전망

  • 장만;신경순;최진우;최동림;이택견;현상민;오재룡;심원준;권개경
    • Proceedings of the Korea Society of Environmental Biology Conference
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    • 2002.11a
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    • pp.9-14
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    • 2002
  • 우리나라의 남해안과 서해안과 같이 해안선의 굴곡이 많고 강의 하류 부분에 위치한 연안 해양은 육지로부터 영향을 가장 많이 받는다. 강 하류에 위치한 항만은 이 지역을 중심으로 발달한 도시와 각종 산업시설과 대규모 부두 시설에 의해 직접 오염물질이 유입되고, 반 폐쇄적인 지리적인 조건으로 오염 물질의 외부 확산이 적게 일어남으로써 각종 유해 오염물질의 최종 종착지이자 오염물질의 보유고 역할을 하고 있다. 본 과제의 주요 목표는 오염지역의 오염물 이동 및 생태계 구조 변화에 관한 종합적 분석을 통해 오염우심해역 관리를 위한 오염과 생태환경에 대한 종합적인 지침서 (오염물 분포, 이동, 순환 등) 제시하고, 오염물질의 순환과정에서 수생-저서생태계의 연계성 규명하며, 더 나아가서 국가실천계획 (NPA) 이행을 위한 기반 확립이다. 본 연구과제의 결과는 항상 오염에 노출될 가능성이 높은 연안역관리를 위한 지표자료를 제공하며, 앞으로 국제적으로 규제될 각종 유기오염물질관리를 위한 자료로 활용될 것이다.

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