• Journal of Microbiology and Biotechnology
• /
• 제14권6호
• /
• pp.1114-1119
• /
• 2004

The biofilms on pipe walls in water distribution systems are of interest since they can lead to chlorine demand, coliform growth, pipe corrosion, and water taste and odor problems. As such, the study described in this paper is part of an AWWARF and Tampa Bay Water tailored collaboration project to determine the effect of blending different source waters on the water quality in various distribution systems. The project was based on 18 independent pilot distribution systems (PDS), each being fed by a different water blend (7 finished waters blended in different proportions). The source waters compared were groundwater, surface water, and brackish water, which were treated in a variety of pilot distribution systems, including reverse osmosis (RO) (desalination), both membrane and chemical softening, and ozonation-biological activated carbon (BAC), resulting in a total of 7 different finished waters. The observations from this study consistently demonstrated that unlined ductile iron was more heavily colonized by a biomass than galvanized steel, lined ductile iron, and PVC (in that order) and that the fixed biomass accumulation was more influenced by the nature of the supporting material than by the water quality (including the secondary residual levels). However, although the bulk liquid water cultivable bacterial counts (i.e. heterotrophic plate counts or HPCs) did not increase with a greater biofilm accumulation, the results also suggested that high HPCs corresponded to a low disinfectant residual more than a high biofilm inventory. Furthermore, temperature was found to affect the biofilms, plus the AOC was important when the residual was between 0.6 and 2.0 mg $Cl_2/l$. An additional aspect of the current study was that the potential of the exoproteolytic activity (PEPA) technique was used along with a traditional so-called destructive technique in which the biofilm was scrapped off the coupon surface, resuspended, and cultivated on an R2A agar. Both techniques indicated similar trends and relative comparisons among the PDSs, yet the culturable biofilm values for the traditional method were several orders of magnitude lower than the PEPA values.

• 가정과삶의질연구
• /
• 제28권3호
• /
• pp.61-71
• /
• 2010

This thesis seeks to inquire into the effect of group art therapy using a fabric medium on the emotional intelligence of middle school students. This application of fabrics to group art therapy is helpful in terms of gender roles and equality from an educational aspect and can help activate and control positive sentiment. Therefore, it was believed to have a positive effect on emotional intelligence. The subjects were 28 boys and girls who were students of the Supportive Project for the Priority Region of Educational Welfare Investment. The measurement tool is a revision of the emotional intelligence test of Mun Yong-Rin (1997), which itself was based on the emotional intelligence model of Mayer and Salovey (1997). The data materials are analyzed by SPSS (ver. 17.0 for Windows). To test the homogeneity of the groups, the Mann-Whitney U test was carried out, and to analyze the effect of this program, the Wilcoxon signed ranks test was carried out. The results are as follows. This program had a positive effect on the emotional intelligence of both male and female students, especially on their empathy and activation of thinking among the subcategories. This study has significance in that it verifies the effect of the improvement of emotional intelligence by way of group art therapy using fabrics, adding a fabric medium to the art medium. As the subject group was restricted to 28 adolescents in the Supportive Project, it is not easy to generalize the achievement to the entiresphere of group art therapy.

• 한국기록관리학회지
• /
• 제20권4호
• /
• pp.41-58
• /
• 2020

많은 연구에서 행정정보 데이터세트의 중요성을 언급해왔으나 지금까지 실질적인 관리는 전무했다. 이런 상황에서 2020년 국가기록원은 행정정보 데이터세트 관리를 중점 추진사업으로 선정하며 본격적인 관리 작업에 착수하였다. 국가기록원의 노력에도 불구하고 업무를 수행하여야 할 기록관은 새로운 사업에 대한 우려를 보였다. 이에 이 연구에서는 공공기관에서 이미 실시하고 있는 공공데이터 사업과의 비교를 통해 행정정보 데이터세트 관리의 문제점을 확인하고, 개선방안을 찾고자 하였다. 법률, 고시, 지침, 소관 부처에서 발행한 간행물의 내용을 중심으로 대상을 분석, 비교하였다. 분석 결과를 토대로 단위기능 책정시 정부기능분류 참조, 행정정보 데이터세트 관리기준표 재구성, 유관 시스템과의 데이터 연계를 행정정보 데이터세트 관리의 개선방안으로 제안하였다.

• 지역사회간호학회지
• /
• 제12권1호
• /
• pp.49-59
• /
• 2001

Purpose: This study was intended to develop the framework of public health center based 'Child growth and developmental clinic' and analyze the efficiency of services. This was the part of Mother-Child Health Guidance Project by the Public Health Center in Seoul. The purposes of this project were to improve children's health and development with early detection of developmental delay by screening test, and to assist and guide the parent for child care and rearing, so that children can reach their maximum potential. Method: Framework and standards for operation of 'Child growth and development clinic' were developed. We selected screening tool. developed parent education materials, and educated the personnel of public health center. Result: 243 children were enrolled for developmental screening, and we detect the children with developmental delay and referred them for further evaluation. The proportion of developmental delayed children was approximately 2% of the enrolled children. Also, we analyzed the characteristics of enrolled children, and their parental needs and attitude on child rearing. Some problems in operation of developmental clinic were discussed. Conclusion: Though we can found some limitations, we are confident that pubic health center can be charge of important role for improving child development for the majority. This study will be the basis of children's developmental clinic running by public health center.

• 정보교육학회논문지
• /
• 제22권6호
• /
• pp.661-669
• /
• 2018

2015 개정교육과정에 의해 2018년부터 SW 교육이 필수화되면서 SW 교육에 대한 연구가 활발하게 이루어지고 있다. 본 논문에서는 예비교사들의 컴퓨팅 사고력 수준을 파악하기 위해 2016년부터 2018년까지 3년 동안 K 교육대학교 1학년 학생 325명을 대상으로 스크래치 수업을 실시한 후 연도별로 산출된 스크래치 프로젝트를 Dr. Scratch 분석도구로 평가하여 연도별과 학점별로 CT요소 점수의 연관성을 분석하였다. 그 결과, 연도와 학점이 높을수록 CT요소, 점수, 등급도 높아짐을 알 수 있었다. 이를 통해, 학생들은 Dr. Scratch와 같은 자동화된 평가도구를 사용하여 평가해 본 후 스스로 수정 보완해보는 과정과 필요한 자료를 직접 제작하여 활용하는 ICT 능력이 필요하며, 복잡한 조건과 논리연산 활용 등 논리적 사고 요소를 이해하고 잘 활용될 수 있도록 교육될 필요가 있다.

• 국제학술발표논문집
• /
• The 3th International Conference on Construction Engineering and Project Management
• /
• pp.242-249
• /
• 2009

High-rise construction sites, especially those situated in spatially constrained urban areas, have difficulties in timely delivery of materials. Modern techniques such as Just-in-time delivery, and use of information technology such as Project Management Information System (PMIS), are targeted to improve the efficiency of the logistics. Such IT-driven management techniques can be further benefited from state-of-the-art devices such as Radio Frequency Identification (RFID) tags and Ubiquitous Sensor Networks (USN), which has resulted in notable achievements in automated logistics management at the construction sites. Based on those achievements, this research develops USN hardware toolkits for construction lifts, which aims to be automated the vertical material delivery by sensing the material information and routing it automatically to the right place. The gathered information from the sensors can also be used for monitoring the overall status. The developed system will be tested in the actual high-rise construction sites to assess the system's feasibility. The proposed system is being implemented using Zigbee communication modules and RFID sensor networks which will communicate with the intelligent palette system (previously developed by the authors). To support the system, a lift-mountable intelligent toolkit is under development. Its feasibility test will be conducted by applying the implemented system to a test bed and then analyzing efficiency of the system and the toolkit. The collected test data will be provided as a basis of autonomous vertical transport equipment development. From this research, efficient management of the material lift is expected with increased accuracy, as well as better management of overall construction schedule benefited from the system. Further research will be expected to develop a smart construction lift, which will eliminate the need for human supervision, thus enabling a real 'autonomous' operation of the system.

• 국제학술발표논문집
• /
• The 9th International Conference on Construction Engineering and Project Management
• /
• pp.877-885
• /
• 2022

Vision-based activity recognition has been widely attempted at construction sites to estimate productivity and enhance workers' health and safety. Previous studies have focused on extracting an individual worker's postural information from sequential image frames for activity recognition. However, various trades of workers perform different tasks with similar postural patterns, which degrades the performance of activity recognition based on postural information. To this end, this research exploited a concept of human-object interaction, the interaction between a worker and their surrounding objects, considering the fact that trade workers interact with a specific object (e.g., working tools or construction materials) relevant to their trades. This research developed an approach to understand the context from sequential image frames based on four features: posture, object, spatial features, and temporal feature. Both posture and object features were used to analyze the interaction between the worker and the target object, and the other two features were used to detect movements from the entire region of image frames in both temporal and spatial domains. The developed approach used convolutional neural networks (CNN) for feature extractors and activity classifiers and long short-term memory (LSTM) was also used as an activity classifier. The developed approach provided an average accuracy of 85.96% for classifying 12 target construction tasks performed by two trades of workers, which was higher than two benchmark models. This experimental result indicated that integrating a concept of the human-object interaction offers great benefits in activity recognition when various trade workers coexist in a scene.

• 토지주택연구
• /
• 제4권4호
• /
• pp.425-434
• /
• 2013

중소기업청은 일정규모 이상의 공공건설사업에 대해 일반공사와 의무적으로 분리하여 직접 구매해야 하는 123개 공사용자재 제품군을 지정하고, 법에서 정한 바에 따라 발주기관이 자재를 직접 구매하여 수급인에게 공급하도록 하고 있다. 본 연구에서는 이러한 공사용자재 직접구매제도 하에서 공공아파트 건설 현장에 투입되는 지급자재가 지니는 다양한 특성과 관리요인을 발주자 입장에서 종합적으로 고려하여, 주요관리대상 자재를 파악하고, 자재 조달 프로세스를 기반으로 이들에 대한 적정 관리 방안을 제시하였다. 즉, 조달경로, 현장특화정도, 입주자 요구수준, 업체 책임범위, 납품분할정도, 현장작업 요구도, 부속자재 필요도, 검수조건 등 지급자재가 가지는 주요 관리요인을 적용하여 공공아파트 건설사업에 적용되는 43개 직접 구매 대상품목의 조달관리부담을 평가한 결과, 상대적으로 높은 조달관리노력이 요구되는 주요관리대상그룹에는 목재창호, 알루미늄창호, 승강기, 목재마루재, 레미콘, 타일, 합성수지창호가 포함되었고, 그 중 알루미늄창호와 타일은 집중관리대상으로 분류되었다. 나아가 직접구매제도의 영향에 따른 집중관리대상 자재에 대한 대응방안은 발주자 입장에서 실태, 문제점, 관리측면의 주요 고려사항을 반영하여 작성하였으며, 실질적 수량 산출, 명확한 발주세부조건 정비, 생산 전후 활동 활성화, 하자보수 물량 확보, 공종별 간섭 사전 협의 및 해소 등이 필수적인 관리활동으로 나타났다.

• 한국건설관리학회논문집
• /
• 제24권6호
• /
• pp.66-73
• /
• 2023

건설 프로젝트는 기획부터 완공까지 공사비 예측, 확인, 그리고 정산 단계로 이루어진다. 건설원자재 평균 가격은 변동성을 지닌다. 하지만 건설 프로젝트의 자재비 산정은 계획단계 시점의 시세를 반영하여 결정되기 때문에, 시공단계에서 자재가 투입될 시점의 시세 변동에 따라 예상한 가격과 차이가 날 수 있다. 건설 산업은 건설원자재 가격 변동으로 인한 수요예측 실패, 프로젝트 비용변경으로 인한 사용자 비용 증가, 예측 체계성 부족으로 인한 손실이 발생한다. 이에 따라 건설원자재 가격 예측의 정확도 개선이 필요하다. 본 연구는 Data Refactor 기법의 개선을 통해 건설원자재 가격 예측 및 적용성 검증을 목적으로 한다. 건설원자재의 가격 예측의 정확도를 높이기 위하여 기존의 데이터 리팩토 간의 저·고빈도의 분류 및 ARIMAX 활용법을 빈도 위주 및 ARIMA 기법 활용으로 개선하여 건설원자재 목재, 시멘트 등 6개 품목의 단기(미래 3개월), 중기(미래 6개월), 장기(미래 12개월) 가격을 예측하였다. 분석한 결과 개선된 Data Refactor 기법을 기반으로 한 예측값이 오차는 줄었고 변동성은 확장되었다. 따라서, 본 연구에서 제안된 Data Refactor 기법을 통해 건설원자재 가격을 더 정확하게 예측하여 예산을 효과적으로 관리할 수 있을 것으로 기대된다.

• 한국분말야금학회:학술대회논문집
• /
• 한국분말야금학회 2000년도 춘계학술강연 및 발표대회 강연 및 발표논문 초록집
• /
• pp.9-10
• /
• 2000

An important business-field of world-wide steel-industry is the coating of thin metal-sheets with zinc, zinc-aluminum and aluminum based materials. These products mostly go into automotive industry. in particular for the car-body. into building and construction industry as well as household appliances. Due to mass-production, the processing is done in large continuously operating plants where the mostly cold-rolled metal-strip as the substrate is handled in coils up to 40 tons unwind before and rolled up again after passing the processing plant which includes cleaning, annealing, hot-dip galvanizing / aluminizing and chemical treatment. In the liquid Zn, Zn-AI, AI-Zn and AI-Si bathes a combined action of corrosion and wear under high temperature and high stress onto the transfer components (rolls) accounts for major economic losses. Most critical here are the bearing systems of these rolls operating in the liquid system. Rolls in liquid system can not be avoided as they are needed to transfer the steel-strip into and out of the crucible. Since several years, ceramic roller bearings are tested here [1.2], however, in particular due to uncontrollable Slag-impurities within the hot bath [3], slide bearings are still expected to be of a higher potential [4]. The today's state of the art is the application of slide bearings based on Stellite\ulcorneragainst Stellite which is in general a 50-60 wt% Co-matrix with incorporated Cr- and W-carbides and other composites. Indeed Stellite is used as the bearing-material as of it's chemical properties (does not go into solution), the physical properties in particular with poor lubricating properties are not satisfying at all. To increase the Sliding behavior in the bearing system, about 0.15-0.2 wt% of lead has been added into the hot-bath in the past. Due to environmental regulations. this had to be reduced dramatically_ This together with the heavily increasing production rates expressed by increased velocity of the substrate-steel-band up to 200 m/min and increased tractate power up to 10 tons in modern plants. leads to life times of the bearings of a few up to several days only. To improve this situation. the Mechanical Alloying (MA) TeChnique [5.6.7.8] is used to prOduce advanced Stellite-based bearing materials. A lubricating phase is introduced into Stellite-powder-material by MA, the composite-powder-particles are coated by High Energy Milling (HEM) in order to produce bearing-bushes of approximately 12 kg by Sintering, Liquid Phase Sintering (LPS) and Hot Isostatic Pressing (HIP). The chemical and physical behavior of samples as well as the bearing systems in the hot galvanizing / aluminizing plant are discussed. DependenCies like lubricant material and composite, LPS-binder and composite, particle shape and PM-route with respect to achievable density. (temperature--) shock-reSistibility and corrosive-wear behavior will be described. The materials are characterized by particle size analysis (laser diffraction), scanning electron microscopy and X-ray diffraction. corrosive-wear behavior is determined using a special cylinder-in-bush apparatus (CIBA) as well as field-test in real production condition. Part I of this work describes the initial testing phase where different sample materials are produced, characterized, consolidated and tested in the CIBA under a common AI-Zn-system. The results are discussed and the material-system for the large components to be produced for the field test in real production condition is decided. Outlook: Part II of this work will describe the field test in a hot-dip-galvanizing/aluminizing plant of the mechanically alloyed bearing bushes under aluminum-rich liquid metal. Alter testing, the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed. Part III of this project will describe a second initial testing phase where the won results of part 1+11 will be transferred to the AI-Si system. Part IV of this project will describe the field test in a hot-dip-aluminizing plant of the mechanically alloyed bearing bushes under aluminum liquid metal. After testing. the bushes will be characterized and obtained results with respect to wear. expected lifetime, surface roughness and infiltration will be discussed.