• 제목/요약/키워드: Economic Scale

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금융시장 예측을 위한 시계열자료의 변환기법 융합을 이용한 패턴 모델 결정 (Determination of Pattern Models using a Convergence of Time-Series Data Conversion Technique for the Prediction of Financial Markets)

  • 전진호;김민수
    • 디지털융복합연구
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    • 제13권5호
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    • pp.237-244
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    • 2015
  • 수출주도정책, FTA 체결 및 규제개선 등과 같은 다양한 시장지향적인 정책을 통해 경제시장의 규모가 지속적으로 커졌다. 이에 따라 올바른 의사결정을 위하여 경제시장을 정확하게 분석, 예측하는 문제가 중요한 이슈가 되었다. 경제시장을 표현하는 여러 지표 중 가장 대표적인 주식지표의 정확한 분석 및 의사결정을 위하여 시계열자료의 모델링에 적합한 은닉마아코프모델을 토대로 자료 내에 내재된 예외적인 특징과 잡음을 제거하기 위한 변환기법의 융합모델을 제안하여 모델 추정과 예측 문제에 적용하였으며 그 유효성을 확인하였다. 실험 결과를 통해, 본 연구에서 제안하는 변환조합을 적용하는 모델추정 기법이 유효한 모델 상태 추정 결과를 보여주었으며 실제 코스피지수와 예측의 문제에서도 매우 유사한 운동양태를 확인할 수 있었다.

Use of Adaptive Meshes in Simulation of Combustion Phenomena

  • Yi, Sang-Chul;Koo, Sang-Man
    • 한국결정성장학회:학술대회논문집
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    • 한국결정성장학회 1996년도 제11차 KACG 학술발표회 Crystalline Particle Symposium (CPS)
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    • pp.285-309
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    • 1996
  • Non oxide ceramics such as nitrides of transition metals have shown significant potential for future economic impact, in diverse applications in ceramic, aerospace and electronic industries, as refractory products, abrasives and cutting tools, aircraft components, and semi-conductor substrates amid others. Combustion synthesis has become an attractive alternative to the conventional furnace technology to produce these materials cheaply, faster and at a higher level of purity. However he process os highly exothermic and manifests complex dynamics due to its strongly non-linear nature. In order to develop an understanding of this process and to study the effect of operational parameters on the final outcome, numerical modeling is necessary, which would generated essential knowledge to help scale-up the process. the model is based on a system of parabolic-hyperbolic partial differential equations representing the heat, mass and momentum conservation relations. The model also takes into account structural change due to sintering and volumetric expansion, and their effect on the transport properties of the system. The solutions of these equations exhibit steep moving spatial gradients in the form of reaction fronts, propagating in space with variable velocity, which gives rise to varying time scales. To cope with the possibility of extremely abrupt changes in the values of the solution over very short distances, adaptive mesh techniques can be applied to resolve the high activity regions by ordering grid points in appropriate places. To avoid a control volume formulation of the solution of partial differential equations, a simple orthogonal, adaptive-mesh technique is employed. This involves separate adaptation in the x and y directions. Through simple analysis and numerical examples, the adaptive mesh is shown to give significant increase in accuracy in the computations.

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신증후군 환아 어머니의 교육요구와 간호사가 인지한 교육활동의 중요도에 관한 탐색적 연구 (The Educational Needs of Mothers of Nephrotic Syndrome Patients and the Degree of the Importance of Educational Activity Perceived by Nurses)

  • 성미혜;정연
    • Child Health Nursing Research
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    • 제3권2호
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    • pp.169-177
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    • 1997
  • This is descripitive study conducted to identify educational needs of mothers of nephrotic syndrome patients and the degree of the importance of educational activity perceived by nurses who look after nephrotic syndrome patients. The study subjects were composed of 60 mothers & 63 nurses of nephrotic syndrome patients whose children were hospitalized in 2 Pediatric wards of University Hospital in Seoul and 1 in Pusan from Mar. in 1997 to July 1997. A questionaire for this study was item Kikert type 5 point scale, developed on the basis of previous literature and researcher's clinical experience and the reliability of the used instruments was α=.97. The data analysis was done by SAS. t-test, and ANOVA were done to determine the effect of general characteristics of subjects on their educational needs. T-test was done to measure relations between the degree of educational needs and importance of educational activity. The results were as follows. 1. The Educational needs of mothers ranked as the highest in home care. 2. In character of mothers, the degree of education, economic state, the number of child and occupation was significant in statistically. 3. The importance of educational activity of nurses ranked the highest in diagnosis and treatment of the disease. 4. The educational needs of nephrotic syn. children' mother and importance of nurses were different in diagnosis and treatment of the disease and home care. On the basis of these results, we suggest as follows. 1. It is proposed that nurses use these results of the study actively for the educational program for Nephrotic Syndrome patients and their mothers. 2. It is suggested to make a comparative study of the degree of nurses' understanding of the importance on educational items with the instruments of this study.

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정상체중출생아와 저체중출생아의 영아기 기질 비교 (Comparison of Temperament in Infancy between the normal Infants and Low-birth-weight)

  • 방경숙;전경자
    • 부모자녀건강학회지
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    • 제5권1호
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    • pp.50-61
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    • 2002
  • The purpose of this study was to compare the temperamental differences between the normal infants and low-birth-weight infants. The subjects of this study were 70 mothers with normal infants and 62 mothers with the low-birth-weight. Convenient sampling was done at three regions. The infant temperament scale developed by Pridham & others (1994) was used. Data were analyzed by SPSS WIN program. The results were as follows; 1) There was a significant difference in total temperament score between the low-birth-weight infants and normal infants. The scores of the low-birth-weight infants were significantly lower than those of normal infants in the subscales of amenability and persistence, activity, and reactivity. In adaptability, there was no significant difference between two groups. 2) In both groups, there were no significant difference by socio-economic status of parents, delivery type, and birth order. But, in the case of low-birth-weight infants, the temperament score of infants over 6 months was significantly higher than that of infants under 6 months. 3) In the correlation analysis among subscales of the temperament, amenability and persistence, activity, and reactivity showed the significant relationship. But adaptability showed significant correlation only with the amenability and persistence. In conclusion, temperament score of low-birth-weight infants were significantly lower than that of normal infants. It was suggested that parenting education for low-birth-weight infants would be needed to understand and impact the positive infant temperament.

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Improving Accident Tolerance of Nuclear Fuel with Coated Mo-alloy Cladding

  • Cheng, Bo;Kim, Young-Jin;Chou, Peter
    • Nuclear Engineering and Technology
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    • 제48권1호
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    • pp.16-25
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    • 2016
  • In severe loss of coolant accidents (LOCA), similar to those experienced at Fukushima Daiichi and Three Mile Island Unit 1, the zirconiumalloy fuel claddingmaterials are rapidlyheateddue to nuclear decay heating and rapid exothermic oxidation of zirconium with steam. This heating causes the cladding to rapidly react with steam, lose strength, burst or collapse, and generate large quantities of hydrogen gas. Although maintaining core cooling remains the highest priority in accident management, an accident tolerant fuel (ATF) design may extend coping and recovery time for operators to restore emergency power, and cooling, and achieve safe shutdown. An ATF is required to possess high resistance to steam oxidation to reduce hydrogen generation and sufficient mechanical strength to maintain fuel rod integrity and core coolability. The initiative undertaken by Electric Power Research Institute (EPRI) is to demonstrate the feasibility of developing an ATF cladding with capability to maintain its integrity in $1,200-1,500^{\circ}C$ steam for at least 24 hours. This ATF cladding utilizes thin-walled Mo-alloys coated with oxidation-resistant surface layers. The basic design consists of a thin-walled Mo alloy structural tube with a metallurgically bonded, oxidation-resistant outer layer. Two options are being investigated: a commercially available iron, chromium, and aluminum alloy with excellent high temperature oxidation resistance, and a Zr alloy with demonstratedcorrosionresistance.Asthese composite claddings will incorporate either no Zr, or thin Zr outer layers, hydrogen generation under severe LOCA conditions will be greatly reduced. Key technical challenges and uncertainties specific to Moalloy fuel cladding include: economic core design, industrial scale fabricability, radiation embrittlement, and corrosion and oxidation resistance during normal operation, transients, and severe accidents. Progress in each aspect has been made and key results are discussed in this document. In addition to assisting plants in meeting Light Water Reactor (LWR) challenges, accident-tolerant Mo-based cladding technologies are expected to be applicable for use in high-temperature helium and molten salt reactor designs, as well as nonnuclear high temperature applications.

유배우 근로자의 직업만족도와 결혼만족도 (Job Satisfaction and Marital Satisfaction among married Employers)

  • 박은옥
    • 지역사회간호학회지
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    • 제12권3호
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    • pp.661-669
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    • 2001
  • Purpose: This study was carried out to investigate the difference in job satisfaction and marital satisfaction by gender and to explore the influences of demographic status. employment characteristics. and job satisfaction/marital satisfaction on each type of satisfaction. Method: Social statistics survey data collected by National Statistical Office in 1998 were used for the secondary analysis in the study. Job satisfaction was measured by questionnaires, which consisted of 12 items such as task, promotion, placement, wage, benefits, future in the work, working environment, human relationship. and working hours. And marital satisfaction was collected by questionnaires which consisted of 7 items, including satisfaction with general family life, relationship with their own parent and parent-in-law, relationship with brothers and sisters, relationship with their children, and economic living status. These are measured by 5-point Likert scale. Result: The results show that more than 60% of women were working as part-time employees. Their education levels were lower than men. Men were satisfied significantly more in their jobs than women. Men also had higher marital satisfaction. The employment status had the most important factor on the job satisfaction. and the marital satisfaction was the second important factor among women and men. As for the age, while older men showed higher job satisfaction, younger women showed higher job satisfaction, 28.04% of the variance in the job satisfaction for men and 33.86% for women were accounted for by the following variables: the younger age. the higher education. job satisfaction, and the higher marital satisfaction, 22.15% of the variance in the marital satisfaction for men and 21.19% for women were accounted for by these variables. Conclusion: The results of this study showed that there were differences in job satisfaction and marital satisfaction between genders, and that job satisfaction and marital satisfaction influenced each other. Employment status was the most predictive factor on the job satisfaction. Married women had an unstable employment status such as part-time position. The stability of employment could be considered as a strategy for enhancing job satisfaction for both sexes. The reason that women had lower marital satisfaction than men will have to be further investigated.

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슬관절통이 있는 재가노인의 통증과 보행속도 및 관절가동범위 (The Level of Pain, Gait Speed, and ROM in Community-dwelling Older Adults with Knee Joint Pain)

  • 김계하;이진민
    • 지역사회간호학회지
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    • 제28권2호
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    • pp.156-164
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    • 2017
  • Purpose: The purpose of this study is to investigate the level of pain, gait speed, and ROM (Range of motion) in community-dwelling older adults with knee joint pain. Methods: A convenience sample of 160 participants living in G city were recruited. Elderly people who suffer from knee joint pain with a pain level ${\geq}5$ during the last one year on a visual analogue scale were included in the study. The data were collected from June to August 2016. All statistical analyses were performed using IBM SPSS ver. 22.0. Results: Participants' pain was 6.81 by VAS. The mean gait speed was 13.9 sec/10m. The ROM of left knee and right knee were $54.06^{\circ}$ and $56.50^{\circ}$, respectively. The level of pain was different according to gender (t=-4.87, p<.001), economic status (t=3.51, p=.032), diseases (t=5.23, p<.001), diagnosis of arthritis (t=3.86, p<.001), region of knee joint pain (F=9.30, p<.001), duration of pain occurrence (F=13.82, p<.001), and limp (F=3.58, p<.001). The level of knee joint pain and gait speed had significant correlations. Conclusion: The gait speed in older adults is an important variable that should be taken into account in the assessment of their level of knee joint pain.

한국의 신재생에너지 정책의 평가모델 개발 : RPS 및 FIT를 중심으로 (Development of Evaluation Model for the Korean New & Renewable Energy Policies : Focusing on RPS & FIT)

  • 최종재;황찬규;문채주
    • 한국전자통신학회논문지
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    • 제8권9호
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    • pp.1333-1342
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    • 2013
  • 신재생에너지산업의 발전은 에너지원의 문제를 해결하기 위한 필수적인 과제라 할 수 있다. 이에 따라 세계 각국에서 신재생에너지산업을 위해 적극적으로 움직이고 있다. 신재생에너지산업은 아직 산업기반이 약하고, 산업의 특성상 규모의 경제 및 기술개발을 위한 초기 투자가 필요한 경우가 많다. 따라서, 신재생에너지산업을 육성하기 위한 정책이 실행되고 있는데 우리나라 뿐만 아니라 많은 나라에서 대표적으로 실행하는 정책이 RPS와 FIT 정책이다. 신재생에너지산업은 다양한 이해관계와 경제, 사회, 환경, 국제 등의 변수를 동시에 가지고 있으므로 이를 종합적으로 고려한 정책이 필요하다. 신재생에너지산업의 경우 평가의 지표에 해당하는 부분이 많고 고려되어야 할 변수가 많으나, 이를 모두 고려하기 힘들고 고려한다 하더라도 일관된 기준이 마련되어 있지 않은 상황이다. 따라서, 본 연구에서는 신재생에너지정책을 평가하기 위한 평가지표를 개발, 제시한다.

무선 통신 기반 스마트 농장 온습도 제어 방법론에 대한 연구 (A Study on the Temperature and Humidity Control Methodology of Smart Farm ased on Wireless Communication Network)

  • 박세현;오성현;이상민;맹준석;고윤석
    • 한국전자통신학회논문지
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    • 제13권4호
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    • pp.851-858
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    • 2018
  • 본 논문에서는 스마트 농장의 경제성과 생산성을 제고하기 위한 스마트 농장을 위한 온습도 제어 알고리즘을 제안하였다. 스마트 농장의 기본 조건을 분석하고, 이를 기반으로 무선통신을 기반으로 하는 스마트 농장내의 센서 및 제어대상간 정보교환 시스템을 설계하였으며, 스마트 농장내의 온도, 습도 그리고 토양습도가 식물 성장에 적합하게 설정된 기준 값을 추종하도록 온습도 제어 알고리즘을 개발하였다. 제안된 설계 방법론 및 제어 알고리즘의 유효성을 검증하기 위해서 2.4GHz 무선통신 기반 소규모 스마트 농장의 프로토타입을 제작하였으며, 온습도 실험을 통해서 그들의 유효성을 확인하였다.

주택문화관의 지역복합커뮤니티센터로서의 활용가능성에 관한 연구 (A Study on the Development Activation Plan of Housing Cultural Center as Local Complex Community Center)

  • 신해철;박경난;김문덕
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2008년도 춘계학술발표대회 논문집
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    • pp.116-122
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    • 2008
  • As a model house has attempted a role change from a conceptual perspective as a housing cultural center starting from the 90ties, it began to direct the change into a high end building. In particular, large construction companies have recently invested on an unimagined scale, unlike in the past, in building a model house and pursued the construction of new attractions of cities as well as the upgrade of a brand image by hiring and implementing the designs of celebrity architects or designers. In addition, they have been in pursuit of a change by enhancing the satisfaction and pride of residents by offering spaces and programs for various cultural arts for apartment residents or potential customers and having them participate in those programs. This study aims to expound on the possibility of the utilization of a housing cultural center as a local complex community center by analyzing the spatial organization and the operational program of a housing cultural center appearing since the 90ties. With this aim, the study analyzed the cases of a complex community center and the program and the operational method of a housing cultural center within the case study in order to propose the possibilities for the utilization of a local complex community center. The elevation of the cultural and economic level of citizens and a rapid social change are shown as various demands for welfare, and the subsequent social physical change has led to the expansion of a space as a complex community. A housing cultural center is also directed to grow as a complex community center from the perspective of diverse demands and participations of consumers, and prepares a field for a broad spectrum of communications from the perspective of housing and cities.

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