• 제목/요약/키워드: scale variable

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Analysis of the Control Variables for Natural Gas Liquefied Process Using Mixed Refrigerant (혼합냉매를 이용한 천연가스 액화공정의 제어변수 분석)

  • Lee, Jae Yong;Kim, Mun-Hyun;Park, Chan-Cook
    • Journal of the Korean Institute of Gas
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    • v.17 no.4
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    • pp.51-57
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    • 2013
  • The process of liquefied natural gas is less then $-160^{\circ}C$ to natural gas by cooling at atmospheric pressure. When control strategy was made, one of the most significant is analysis of process. It is important to understand the control variable change according to manipulated variable change. In this study, we experiment natural gas liquefied process using C3MR(Propane Pre-cooled Mixed Refrigerant) process by BSU(Bench Scale Unit). We analyzed the change of refrigerant temperature and natural gas temperature according to the change of refrigerant flow rate so as to search an influence flow rate according to adjust each manipulated variables. One of the manipulated variable affected a number of control variables, but were able to confirm a control variable with a large response.

Deduction of Change Management Factors and Weight Estimation based on ANP in Urban Renewal Project (ANP 기반 도시환경정비사업의 변화관리 요인 도출 및 중요도 산정)

  • Shin, Seung-Yoon;Son, Myung-Jin;Hyun, Chang-Taek
    • Korean Journal of Construction Engineering and Management
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    • v.14 no.3
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    • pp.176-186
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    • 2013
  • For urban renewal projects progressing in large scale, it carries a characteristic that frequently changes the environment, subject, law, plan and the like by a demand from various participants and internal/external factors. As such large-scale urban renewal projects have a lot of possibilities of change, it requires setting a plan to recognize the possible variable factors by each project operation stage and to manage it systematically by defining the variable factors on the basis of working process of the entire project. Therefore this research has produced a factor of main variable management based on working process for systematic variable management on the projects that inherent various possibilities of change as urban environment refurbishment projects. And it also suggests the status of main variable factors characterized by project operation stages quantitatively through reflecting external and internal features for variable factors produced from utilizing ANP methodology.

Variable Time-Scale Modification of Speech Using Trasient Information (천이구간 정보를 이용한 음성의 가변적인 시간축 변환)

  • Lee, Sung-Joo;Kim, Hee-Dong;Kim, Hyung-Soon
    • Journal of the Korean Institute of Telematics and Electronics S
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    • v.35S no.6
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    • pp.147-155
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    • 1998
  • Conventional time-scale modification methods have the problem that as the modification rate gets higher the time-scale modified speech signal becomes less intelligible, because they ignore the effect of articulation rate on speech characteristics. In this paper, we propose a variable time-scale modification method based on the knowledge that the timing information of transient portions of a speech signal plays an important role in speech perception. After identifying steady protions only. The result of subjective preference test indicates that the proposed method produces performance superior to that of the conventional SOLA method.

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Performance Relation Analysis of CLR, Buffer Capacity and Delay Time in the ATM Access Node (ATM 접속노드에서 셀 손실율과 버퍼용량 및 지연시간의 상관관계 분석)

  • 이하철;이병섭
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.27 no.10C
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    • pp.945-950
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    • 2002
  • In this paper the performance evaluations on Asynchronous Transfer Mode(ATM) access node are performed in the ATM access network which consists of access node and channel. The performance factors of access node are Cell Loss Ratio(CLR), buffer capacity and delay time. Both the ATM cell-scale queueing model and burst-scale queueing model are considered as the traffic model of access node for various traffic types such as Constant Bit Rate(CBR), Variable Bit Rate(VBR) and random traffic in the ATM access networks. Based on these situations, the relation of CLR, buffer capacity and delay time is analyzed in the ATM access node.

Significant Variables Influencing the Self-Efficacy of Middle School Students of Multicultural Families (다문화가정 중학생 자녀의 자기효능감에 영향을 미치는 요인 연구)

  • Jun, Jong Mi;Chang, Jin Kyung
    • Human Ecology Research
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    • v.51 no.3
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    • pp.333-340
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    • 2013
  • The purpose of this study is to identify the influences of parental attitude, parenting attitudes, family function and peer attachment on the self-efficacy of middle school students in multicultural families. In particular, peer attachment was used as a mediator to determine the effects of self-efficacy. 302 multicultural family adolescents who enrolled in Seoul and Gyeonggi-do middle schools were surveyed. In order to measure the variables, this study used such scales as parenting attitude scale, family function scale, peer attachment scale and self efficacy scale. The results were analyzed by the PASW 18.0 program. The findings of the study led to the following conclusions; First, it has shown that peer attachment was the only variable that had significant differences by sex in middle school students of multicultural families. Second, the most influential variables of self-efficacy of middle school students in multicultural families was peer attachment among parenting attitude, family function and peer attachment. Third, there was a mediating effect of peer attachment among parenting attitude, family function and self-efficacy for adolescents of multicultural families. The notable distinction of this study was to find that peer attachment variable is the most important factor of self-efficacy. Considering the results in this study, aggressive intervention is necessary in order to improve the self-efficacy of middle school students in multicultural families.

A review on dynamic characteristics of nonlocal porous FG nanobeams under moving loads

  • Abdulaziz Saud Khider;Ali Aalsaud;Nadhim M. Faleh;Abeer K. Abd;Mamoon A.A. Al-Jaafari;Raad M. Fenjan
    • Steel and Composite Structures
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    • v.50 no.1
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    • pp.15-24
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    • 2024
  • This research presents dynamical reaction investigation of pore-dependent and nano-thickness beams having functional gradation (FG) constituents exposed to a movable particle. The nano-thickness beam formulation has been appointed with the benefits of refined high orders beam paradigm and nonlocal strain gradient theory (NSGT) comprising two scale moduli entitled nonlocality and strains gradient modulus. The graded pore-dependent constituents have been designed through pore factor based power-law relations comprising pore volumes pursuant to even or uneven pore scattering. Therewith, variable scale modulus has been thought-out until process a more accurate designing of scale effects on graded nano-thickness beams. The motion equations have been appointed to be solved via Ritz method with the benefits of Chebyshev polynomials in cosine form. Also, Laplace transform techniques help Ritz-Chebyshev method to obtain the dynamical response in time domain. All factors such as particle speed, pores and variable scale modulus affect the dynamical response.

Error-Diffusion Technique using Variable Principle Distances for LCD Monitor (액정디스플레이를 위한 가변 주거리 기반의 오차 확산 기법)

  • Yoon, Jo-Seph;Park, Gyeong-Mi;Kim, Young-Bong
    • Journal of Korea Multimedia Society
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    • v.12 no.3
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    • pp.362-371
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    • 2009
  • The key technology for developing high quality LCDs is about manufacturing BLUs with homogeneous dot distributions. Commonly, homogeneous dot distributions are obtained by the halftoning methods which convert a gray-scale image to a binary image. Among many halftoning algorithms, the error-diffusion technique based on the principle distance is known to show homogeneous dot distributions. However, this technique has a drawback; the extent of the principle distance at each pixel with respect to those of the neighboring pixels can be too small or big creating a gap or overlap. In this paper, we propose a new error diffusion algorithm based on the variable principle distance which improves the existing error diffusion technique based on the principle distance. The variable principle distance at a given pixel is calculated with gray-scale values of the pixel and its neighbors and thus the principle distance value is variable depending on the direction from that pixel. This variable principle distance technique helps BLUs obtain homogeneous dot distributions.

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A Study on Factors Affecting Dental Hygienists' Job Stress (치과위생사의 직무 스트레스에 영향을 미치는 요인 분석)

  • 이성숙
    • Korean Journal of Health Education and Promotion
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    • v.15 no.1
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    • pp.151-163
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    • 1998
  • The purpose of this study is to find options which reduce the job stress and to enhance morale through a variable analysis, and also apply this data in the legal and administration fields. The data for the research was obtained from 217 dental hygienists working in the dental clinics, dental hospitals and university's dental hospitals' in Seoul. The tool used by this study was a Questionnaire measuring on-the-job stress of dental hygienists, was a modified and revised. The Questionnaire version used to measure bank's job stress and used to suggest options by Dae-ha Yoon(1991). Classification of items for measuring job stress was based on Theoretical Study on Job Stress by Dae-hyon Song(1986). The scale used in study was the two points (yes or no in the job stress) scale measuring for variables. The period of data collection was 30 days from December 4, 1995 to January 5, 1996. The methods of data collection were self-writing, direct visit, and postal Questionnaire answering, 224 copies of Questionnaire data were collected, but only 217 copies were used. 7 copies could not be analyzed, were not used for this study. The data analysis was conducted by SPSS after coding the collected raw data. The general characteristics was obtained from real digits and percentages. In order to analyze the difference of sub-variables against the job stress based on general characteristics. Mean, Standard Deviation, and F test (ANDVA) were conducted. The following were the results of job stress variables: 1. Meaningful variable affecting the working organization, is compensation system(p〈0.03). 2. Meaningful variable affecting the working period, is work overload(p〈0.02). 3. Meaningful variable affecting average patients per day, is the career management and payment(p〈0.04, p〈0.01). 4. Meaningful variable affecting number of staff, is the comrade relationship, role conflict among patients, work overload, and job overload(p〈0.000, p〈0.05, p〈0.04, p〈0.01). The comrade relationship is most affected to the number of staffs aides. 5. Meaningful variables affecting job diversion, are the desire and value, the non-role play, and the environment(p〈0.003, p〈0.02, p〈0.005).

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Characteristics of Purchasers and Non-Purchasers of Environmental Products (환경상품 구매자와 비구매자의 특성 비교 분석)

  • 안창희;정순희
    • Journal of Families and Better Life
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    • v.22 no.1
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    • pp.55-64
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    • 2004
  • The major purpose of this study was to investigate purchasing behavior of environmental products by Korean consumers, which will ultimately help foster sustainable consumption. Environmental consciousness, environmental behaviors, level of awareness of environmental products, and purchasing of environmental products were examined. Mean differences between purchasers and non-purchasers of environmental products were compared in terms of environmental consciousness and behaviors, and the level of awareness of environmental products. A survey was conducted on 310 consumers in the greater Seoul metropolitan area. The data were analyzed by frequencies, percentages, logistic regression, and t-tests using a variable for interval scale and a variable for nominal scale. There were significant mean differences between purchasers and non-purchasers of environmental products on three variables of environmental consciousness and behaviors. Those who were educated on environmental issues showed a higher preference in purchasing environmental products. Among socio-demographic variables, the income level was the only variable that showed a significant mean difference between the two groups. Also, there was a remarkable difference in purchasing behavior between the two groups. For the purchasers of environmental products, the purchasing decisions took into account environment-friendliness of products. Non-purchasers of environmental products put more emphasis on price or quality of products. The results of the logistic regression analysis indicated that those who had higher education, who viewed environmental pollution as a serious problem, and who are more cognizant of the environmental labeling tend to purchase more environmental products.