• Title/Summary/Keyword: Functional Equation

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Determinants of Reduced Bone Mass in Postmenopausal Women with Rheumatoid Arthritis (폐경 후 류마티스 관절염 여성의 골량감소 판별요인)

  • Lee, Eun-Nam
    • The Korean Journal of Rehabilitation Nursing
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    • v.2 no.2
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    • pp.193-205
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    • 1999
  • This study was carried out to identify the important risk factors for reduced bone mass of postmenopausal RA patients and to develop discriminant function which can classify postmenopausal RA patients with either reduced or normal bone mass. Through the literature review, individual characteristics such as age, body weight, height, age of menarche, duration of menopause, gravity, parity, and breast feeding period and factors of life style such as milk consumption exercise habit, alcohol intake, cigarette smoking, coffee consumpt ion , disease activity, corticosteroid therapy were identified as influencing factors of reduced bone mass in RA patients Sixty eight postmenopausal women with rheumatoid arthritis aged between 42 and 76 were selected among those who checked bone mineral density in lumbar spine and femur from october, 1998 to Apr il, 1999 at Dong-a university hospital in Pusan. Assessment of disease activity, duration of disease and corticosteroid therapy were made by the same rheumatologist and included Ritchie articular index, erythrocyte sedimentation rate, and C-reactive protein on measuring bone mineral density. Cumulative steroid dosage was calculated from the daily dosage multiplied by t h e number of days received. The information of other risk factor including health assessment score, individual characteristics and life style factors were collected by questionnaire. Bone mineral density(BMD) was measured using DXA at lumbar spine and femoral Ward's triangle. Discriminant function(regression equation) was developed for estimating the likelihood of the presence or absence of reduced bone mass. The results are as follows: Among the subjects, thirteen(19.1%) exhibited osteoporosis in lumbar spine and twenty four(35.3%) exhibited osteoporosis in femoral Ward's triangle. For lumbar spine, the variables significant were age, body weight, health assessment score, while for femoral Ward's triangle, age, body weight, duration of disease. But disease activity and corticosteroid therapy were not signigicant to distinguish reduced bone mass from normal bone mass. When the discriminant function was evaluated by comparing the observed out come with predicted out come, the discriminant function correctly classified 85.4% of patients with reduce bone mass and 63.0% of patients with normal bone mass in the lumbar spine and 100% of patients with reduced bone mass and 9.1% of patients with normal bone mass in the femoral Ward's triangle. In summary, we found that osteoporosis in postmenopausal women with RA is more evident at the femur than the lumbar spine. Also the important discriminant factors of reduced bone mass postmenopausal women with RA were age, body weight , duration of disease and health disability. In nursing situation, the efforts to improve of functional capacity of postmenopausal women with rheumatoid arthritis should be considered to prevent osteoporosis and fractures. Also we recommend those postmenopausal women with RA who are classified as a group of the reduced bone mass in the discriminant function should examine the bone mineral density to further examine the usefulness of this discriminant function.

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Motive on Social Networking Service Usage of Restaurant Customers (외식소비자의 소셜네트워킹서비스(SNS) 활용 동기에 관한 연구)

  • Shin, Seo-Young;Cha, Sung-Mi
    • Culinary science and hospitality research
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    • v.19 no.1
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    • pp.121-138
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    • 2013
  • The purpose of this study was to examine the structural relationships among the motives on Social Networking Service(SNS) of restaurants customers, attitude toward SNS, and intention to use. Using a quota sampling method, data were collected from 273 residents of the whole country who were in their 10~50s. The PASW Statistics 18.0 and AMOS 17.0 statistical package were used for the analysis. The hypothesized relationships of the model were tested simultaneously using a structural equation model(SEM). The proposed model provided an adequate fit to the data, ${\chi}^2$=287.558(df=155) p<.000, CMIN/df=1.855 GFI=0.905 NFI=0.887, IFI=0.944, TLI=0.931, CFI=0.943, RMSEA=0.056, RMR=0.025. The results showed that recreational motive(${\beta}$=0.238) and functional motive(${\beta}$=0.467) had a positive effect on the attitude toward SNS. Attitude had a positive effect on the intention of using SNS. The results enable the marketers of restaurants to develop SNS marketing strategies that motivate customers.

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The Analysis of Efficiency and Productivity in the Korean and Japanese Railways: A Stochastic Cost Frontier Approach (확률적 비용변경 접근법을 이용한 한국과 일본 철도산업의 효율성과 생산성 분석)

  • Park, Jin-Gyeong;Kim, Seong-Su
    • Journal of Korean Society of Transportation
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    • v.25 no.6
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    • pp.141-157
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    • 2007
  • This paper evaluates the effects of privatization and deregulation on the firm-specific efficiency and total factor productivity (TFP) growth in the Korean and Japanese railways. Using a stochastic frontier approach and a generalized translog functional form, the paper specifies the equation system consisting of a multiproduct variable cost function and input share equations which is estimated with Zellner's iterative seemingly unrelated regression and the corrected least squares method. The Korean and Japanese railway firms are assumed to produce three outputs (Shinkansen passenger-kilometers, incumbent railway passenger-kilometers, ton-kilometers of freight) using three input factors (labor, fuel, maintenance and rolling stock). A monetary value of the ways and fixed installations held by the railroad firm is also included as a quasi-fixed input. The empirical results indicate that the average estimate of cost inefficiency is 2.57% for the total sample and on the average, JNR and JR Kyushu are found to be worst efficient while the most efficient railway firm in the sample is JR West. Also the cost efficiency levels of seven JRs have been improved after the reform and privatization of JNR. The findings also indicate that TFP growth of the privately-owned JRs are higher than those of the government-owned KNR and JNR. Three-island JRs and JR Freight have slightly higher TFP growth than Honshu JRs as well. Thus, the results suggest that managerial autonomy and increased competition via deregulation have improved efficiency and TFP growth.

An Empirical Study on the Structural Relationship among Corporate Image, Quality Characteristics, Customer Satisfaction, and Customer Royalty in Internet Shopping Malls (인터넷 쇼핑몰의 기업 이미지와 품질특성과 만족도, 충성도의 구조관계에 관한 실증적 연구)

  • Jung, Lee-Sang;Lee, Seok-Yong
    • Management & Information Systems Review
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    • v.28 no.4
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    • pp.175-197
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    • 2009
  • Numerous researches related to internet shopping malls have been researched by numerous researchers. Such as, establishing criteria to evaluate service quality of electronic commerce, identifying factors affecting successful internet shopping mall operation, and examining relationships among the factors in electronic commerce based shopping mall needed to be focused on. However, most researches that have been undertaken only consider the service quality model or basic functional dimension. In accordance with this indispensability, the integrated structural relationship among variables, which are potentially inherent in customer's perception and affect personnel royalty on internet shopping mall needs to be acknowledged. The purpose of this study is to examine which factors should be able to facilitate performance of internet shopping mall. Based on the relevant literature, it has been empirically analyzed how corporate image, system quality, service quality and delivery quality affect customer satisfaction as well as customer royalty. The research's problem is that it was tested with data collected from 212 respondents. This study developed and empirically analyzed a model representing the relationship by using the Structural Equation Model. The major findings of this study are, firstly, that the higher corporate image is positively affecting the system quality and delivery quality. Secondly, the higher delivery quality is positively affecting the service quality. Thirdly, the higher service quality is positively affecting the customer satisfaction. Finally, the higher customer satisfaction is affecting the customer royalty.

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Prediction of Leachate Migration from Waste Disposal Site to Underground LPG Storage Facility and Review of Contamination Control Method by Numerical Simulations (수치모의를 통한 지하 LPG 저장시설에 인접한 폐기물매립지에서의 침출수이동 예측 및 제어공법 검토)

  • 한일영;서일원;오경택
    • Journal of the Korean Society of Groundwater Environment
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    • v.3 no.2
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    • pp.51-59
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    • 1996
  • In case waste disposal site is to be constructed close to the underground facilities such as LPG storage cavern which is completely maintained by groundwater pressure, it is generally requested that the possibility on leachate contamination of cavern area be reviewed and the countermeasure, if it is estimated cavern area is severely affected by leachate, be taken into consideration. Prediction was performed and leachate control plan was made using by analytical and the numerical analysis on the leachate migration which is likely to happen at the area between the proposed waste disposal site and the underground LPG storage cavern located at the U petrochemical complex. Analytical solutions were obtained by the conservative mass advection-diffusion equation and the effect of advection and dispersion factor on the leachate migration was reviewed through peclet number calculation and the functional relationship between the factors and leachate transport velocity was established, which leads to enable us to predict the leachate transport velocity without difficulties when different parameters (factors) are used for analytical solution. Numerical solutions were obtained by FEM using AQUA2D which is for the simulation of groundwater flow and contaminant transport. 3-D discrete fracture models were simulated and fracture flow analysis was performed and feasibility study on the water-curtain system was conducted through the fracture connectivity analysis in rock mass. As results of those analyses, it was interpreted that the leachate would trespass on the LPG storage cavern area in 30 years from the proposed wate disposal site and the vertical water-curtain system was effective mathod for the prevention of leachate's migration further into the cavern area.

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Effect of System Parameters on Target Parameters in Extrusion Cooking of Corn Grit by Twin-Screw Extruder (옥분 압출가공시 이축압출성형기의 System Parameters에 따른 압출물의 특성변화)

  • Kim, Ji-Yong;Kim, Chong-Tai;Kim, Chul-Jin
    • Korean Journal of Food Science and Technology
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    • v.23 no.1
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    • pp.88-92
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    • 1991
  • To analyze the effects of the system parameters on the target parameters, which include the amount of water evaporation, water solubility index(WSI) and water absorption index(WAI), test trials of fractional factorial design of the three process variables at three levels were carried out for corn grit with a laboratory twin-screw extruder with three different screw configurations. The system parameters collected from the trials, such as extrusion temperature, specific mechanical energy input(SME) and mean residence time(RT), were showed the ranges of $129{\sim}182^{\circ}C$, $67{\sim}163\;kwh/ton$ and $12{\sim}34\;sec$, respectively. Within these ranges of the system parameters, the target parameters were able to be quantified by using multiple regression equations. The correlation of results with the system parameters blocked by the screw configuration as dependent variables, yield correlation coefficients above 0.90, and the correlation using the system parameters obtained from whole experiment system as the dependent variables yield correlation coefficients around 0.80. The functional relationship, which can be quantified by second order polynomial regression equation with only two system parameters within necessary degree of accuracy, can he graped in three dimensional surface response and contour diagrams.

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A Novel Method to Assess the Aerobic Gasoline Degradation by Indigenous Soil Microbial Community using Microbial Diversity Information (토양 미생물 다양성 지표를 이용한 토착 미생물 군집의 호기성 가솔린 오염분해능력 평가 기법 개발 연구)

  • Hwang, Seoyun;Lee, Nari;Kwon, Hyeji;Park, Joonhong
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.36 no.5
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    • pp.839-846
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    • 2016
  • Since oil leakage is one of the most common nonpoint pollution sources that contaminate soil in Korea, the capacity of soil microbial community for degrading petroleum hydrocarbons should be considered to assess the functional value of soil resource. However, conventional methods (e.g., microcosm experiments) to assess the remediation capacity of soil microbial community are costly and time-consuming to cover large area. The present study suggests a new approach to assess the toluene remediation capacity of soil microbial community using a microbial diversity index, which is a simpler detection method than measuring degradation rate. The results showed that Shannon index of microbial community were correlated with specific degradation rate ($V_{max}$), a degradation factor. Subsequently, a correlation equation was generated and applied to Michaelis-Menten kinetics. These results will be useful to conveniently assess the remediation capacity of soil microbial community and can be widely applied to diverse engineering fields including environment-friendly construction engineering fields.

The Influential Relationships among the Image, Service Quality, Consumption Value and Customer Emotion in Middle-low Price Chain Hotels (중저가 체인 호텔 이미지가 서비스 품질과 소비가치 및 고객감정에 미치는 영향)

  • Lim, Jong-Woo;Cho, Yong-Bum
    • Culinary science and hospitality research
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    • v.22 no.7
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    • pp.47-57
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    • 2016
  • This study was conducted to verify the relationships among the image of middle-low price chain hotels, service quality, consumption value, and customer emotion by using the AMOS 22.0 statistic package program. Confirmatory factor analysis and structural equation modeling methods employed for identifying the formulated hypothesis model. According to results, first, it is seen that the image of middle-low price chain hotels has positive effect on the service quality. Second, the image of middle-low price chain hotels has positive effect on the consumption value, and the consumption value has positive effect on the service quality. Third, the service quality does not have positive effect on the customer emotion. Last, the image of middle-low price chain hotels has positive effect on the customer emotion. In this study, we attempted to establish the management strategy device of middle-low price chain hotels by analyzing how the image of middle-low price chain hotels affect the service quality, consumption value, and customer emotion. As a result, when it comes to the service quality according to the image of middle-low price chain hotels, the conviction, in other words, the belief of the hotel staffs was the biggest one. In addition, when it comes to the consumption value according to the image of middle-low price chain hotels, the functional value, the kind service of the hotel staffs was seen as the highest satisfaction. More practical and theoretical implications for developing marketing strategy in context of middle-low price chain hotels has been suggested in conclusions.

The Effects of Consumption Value Perceived by Resort Customers on Customer Satisfaction and Behavioral Intention : Focusing on Moderating Effects by Gender and Marital Status (리조트 고객의 소비가치와 고객만족 및 행동의도와의 인과관계 연구: 성별과 결혼유무에 따른 조절효과를 중심으로)

  • Kim, Young-Joong;Kwon, Young-Guk;Yoon, Hye-Hyun
    • Culinary science and hospitality research
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    • v.18 no.3
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    • pp.72-89
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    • 2012
  • This study aims to understand the influence of consumption value perceived by resort customers upon customer satisfaction and behavioral intention. Based on total 324 customers obtained from the empirical research, this study reviewed reliability and fitness of the research model and verified total 4 hypotheses with AMOS program. The hypothesized relationships in the model were tested simultaneously by using a structural equation model(SEM). The proposed model provided an adequate fit to the data, ${\chi}^2$=467.489(p<.001), df=326, CMIN/DF=1.434, GFI=.911, AGFI=.889, NFI=.881, CFI=.960, RMSEA=.037. The model's fit, as indicated by these indexes, was deemed satisfactory, thus it provided a good basic for testing the hypothesized paths. The result showed that the functional value(${\beta}$ .233, p<.01), social value(${\beta}$ .125, p<.05), emotion value(${\beta}$ .310, p<.001), epistemic value(${\beta}$ .144, p<.05) had a positive significant influence on customer satisfaction. Also, customer satisfaction(${\beta}$ .225, p<.01) had a positive significant influence on behavioral intention. The moderating effects by gender and marital status were found not to exist. Limitations and future research directions are also discussed.

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Growth Model of Common Ice Plant (Mesembryanthemum crystallinum L.) Using Expolinear Functions in a Closed-type Plant Production System (완전제어형 식물 생산 시스템에서 선형 지수 함수를 이용한 Common Ice Plant의 생육 모델)

  • Cha, Mi-Kyung;Kim, Ju-Sung;Cho, Young-Yeol
    • Horticultural Science & Technology
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    • v.32 no.4
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    • pp.493-498
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    • 2014
  • The objective of this study was to make growth and yield models for common ice plant (Mesembryanthemum crystallinum L.) using expolinear functional equations in a closed-type plant production system. Three-band radiation type fluorescent lamps with a 12-hours photoperiod were used, and the light intensity was $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Nutrient film systems with three layers were used for plant growth. Environmental conditions, such as air temperature, relative humidity and $CO_2$ concentration were controlled by an ON/OFF operation. Leaf area, shoot fresh and dry weights, light use efficiency of common ice plant as function of days after transplanting, accumulative temperature and accumulative radiation were analyzed. Leaf area, shoot fresh and dry weights per area were described using an expolinear equation. A linear relationship between shoot dry and fresh weights was observed. Light use efficiency of common ice plant was $3.3g{\cdot}MJ^{-1}$ at 30 days after transplanting. It is concluded that the expolinear growth model can be a useful tool for quantifying the growth and yield of common ice plant in a closed plant production system.