• Title/Summary/Keyword: Classification Variables

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Risk factors affecting amputation in diabetic foot

  • Lee, Jun Ho;Yoon, Ji Sung;Lee, Hyoung Woo;Won, Kyu Chang;Moon, Jun Sung;Chung, Seung Min;Lee, Yin Young
    • Journal of Yeungnam Medical Science
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    • v.37 no.4
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    • pp.314-320
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    • 2020
  • Background: A diabetic foot is the most common cause of non-traumatic lower extremity amputations (LEA). The study seeks to assess the risk factors of amputation in patients with diabetic foot ulcers (DFU). Methods: The study was conducted on 351 patients with DFUs from January 2010 to December 2018. Their demographic characteristics, disease history, laboratory data, ankle-brachial index, Wagner classification, osteomyelitis, sarcopenia index, and ulcer sizes were considered as variables to predict outcome. A chi-square test and multivariate logistic regression analysis were performed to test the relationship of the data gathered. Additionally, the subjects were divided into two groups based on their amputation surgery. Results: Out of the 351 subjects, 170 required LEA. The mean age of the subjects was 61 years and the mean duration of diabetes was 15 years; there was no significant difference between the two groups in terms of these averages. Osteomyelitis (hazard ratio [HR], 6.164; 95% confidence interval [CI], 3.561-10.671), lesion on percutaneous transluminal angioplasty (HR, 2.494; 95% CI, 1.087-5.721), estimated glomerular filtration rate (eGFR; HR, 0.99; 95% CI, 0.981-0.999), ulcer size (HR, 1.247; 95% CI, 1.107-1.405), and forefoot ulcer location (HR, 2.475; 95% CI, 0.224-0.73) were associated with risk of amputation. Conclusion: Osteomyelitis, peripheral artery disease, chronic kidney disease, ulcer size, and forefoot ulcer location were risk factors for amputation in diabetic foot patients. Further investigation would contribute to the establishment of a diabetic foot risk stratification system for Koreans, allowing for optimal individualized treatment.

Sensitivity Enhancement of RF Plasma Etch Endpoint Detection With K-means Cluster Analysis

  • Lee, Honyoung;Jang, Haegyu;Lee, Hak-Seung;Chae, Heeyeop
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.142.2-142.2
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    • 2015
  • Plasma etch endpoint detection (EPD) of SiO2 and PR layer is demonstrated by plasma impedance monitoring in this work. Plasma etching process is the core process for making fine pattern devices in semiconductor fabrication, and the etching endpoint detection is one of the essential FDC (Fault Detection and Classification) for yield management and mass production. In general, Optical emission spectrocopy (OES) has been used to detect endpoint because OES can be a simple, non-invasive and real-time plasma monitoring tool. In OES, the trend of a few sensitive wavelengths is traced. However, in case of small-open area etch endpoint detection (ex. contact etch), it is at the boundary of the detection limit because of weak signal intensities of reaction reactants and products. Furthemore, the various materials covering the wafer such as photoresist (PR), dielectric materials, and metals make the analysis of OES signals complicated. In this study, full spectra of optical emission signals were collected and the data were analyzed by a data-mining approach, modified K-means cluster analysis. The K-means cluster analysis is modified suitably to analyze a thousand of wavelength variables from OES. This technique can improve the sensitivity of EPD for small area oxide layer etching processes: about 1.0 % oxide area. This technique is expected to be applied to various plasma monitoring applications including fault detections as well as EPD.

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A study on the behavior of cosmetic customers (화장품구매 자료를 통한 고객 구매행태 분석)

  • Cho, Dae-Hyeon;Kim, Byung-Soo;Seok, Kyung-Ha;Lee, Jong-Un;Kim, Jong-Sung;Kim, Sun-Hwa
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.4
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    • pp.615-627
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    • 2009
  • In micro marketing promotion, it is important to know the behavior of customers. In this study we are interested in the forecasting of repurchase of customers from customers' behavior. By analyzing the cosmetic transaction data we derive some variables which play an important role in the knowledge of the customers' behavior and in the modeling of repurchase. As modeling tools we use the decision tree, logistic regression and neural network model. Finally we decide to use the decision tree as a final model since it yields the smallest RASE (root average squared error) and the greatest correct classification rate.

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An Exploratory Study on the Introduction of Loyalty to Segmentation of Theme Park Users (주제공원 이용자의 시장세분화를 위한 충성도의 사용가능성 검토)

    • Journal of the Korean Institute of Landscape Architecture
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    • v.26 no.1
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    • pp.1-11
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    • 1998
  • The purpose of this paper is twofold : to identify loyalty applicable to segmentation of theme park users and to find characteristics of the segments. Thetheme park was regarded as a product and Lotte World was regarded as a brand. One hundred thirty five college students were selected by nonprobability sampling for two waves thirty of data collection. Both behavioral and attitudinal dimension of loyalty were measured in the first wave by the proportion of visit of the Lotte World to 3 major theme parks for one year, including the Lotte World, and by calculating the mean score of selected 7 attitudinal items, respectively. After 14 weeks, the same respondents were asked the number of actual visits of the Lotte World. Medians of two dimensions and cluster analyses were utilized to classify the respondents into 4 categories : high, spurious, latent, and low loyalty. Then ANOVA and $$\chi$^2$ test of independence were conducted to find the difference in intention to visit the Lotte World and actual visitation of it among groups. Only intention was significantly different by the group and the mean score of intention was highest in the high loyalty group. Although no statistical difference was found in actual visitation among groups, the theory of planned behavior provided a theoretical support to conclude that the loyalty is a useful variable for segmentation of theme park users because intention is an antecedent variable to the behavior. Discriminant analyses showed that characteristics of each loyalty group can be differentiated by motivations and constraints. When median was a group classification criterion, 73.2 percent of high loyalty group was correctly classified. A few comments were suggested on data collection, and inclusion of new discriminant variables was discussed for the future research.

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A Study on the Development of Measurement Instruments for the Business Model of Electronic Commerce in the Strategic Perspective (전략적 관점에서 본 전자상거래 비즈니스 모델의 측정도구 개발에 관한 연구)

  • Song Young-Il;Jeon Ho-Il
    • The Journal of Information Systems
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    • v.15 no.3
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    • pp.1-34
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    • 2006
  • The purpose of this study Is to develop empirically validated instrument for business model. The previous researches related to business model were almost taxonomies. And the focus of those researches were the classification by the degree of integration and innovation the origin, and the main source of revenue etc. In the emerging fields such as IT, e-commerce, and e-business, it tends to overlook methodological issue in its substantive relationships and also measurement. Business model is taken an interest in recent years. However, as the non-establishment of construct on business model has made no empirical study, this, study tries to develop an empirical validated instrument that identifies the dimensions of business model by uncovering meaningful group or categories. For this, the outlined domain of business model are defined as an organizational level that competes in the industry through the literature reviews. And the traits such as process integration, value chain reconstruction, strategic alliance with another business model, specialty in a certain wet sustainability of essential capabilities, differentiation, convertibility, customer orientation, revenue stream, newness, innovation leadership: and vision sharing are identified in those respective domains, and then the traits are classified into five dimensions such as interlinkageableness, valueness, functionalness, preemptiveness, and goalness by their characteristics. Generating items are continued on the basis of operationalization. Confirmatory factor analysis is performed in order to develop validated instrument with LISREL measurement model. Finally the instrument is developed through the previous procedure. The implication of this study is the first empirical effort to assess business model. The resulting instrument can be used with dependent variables in the future study related to business model. And the establishment of construct of business model is able to make a basis to rise an additional issue consequently. In the practical side, the instrument also can be employed as an assessment framework that can assess whether the expected value success or not. The instrument with the measurement can be used on competitor's business model, In. When an investment into a i-m with a specific business model, these instrument developed can be presented as the basic framework of assessment.

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Effectiveness of Computed Tomography for Blow-out Fracture

  • Rhee, Seung-Hyun;Kim, Tae-Seup;Song, Jae-Min;Shin, Sang-Hoon;Lee, Jae-Yeol
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.36 no.6
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    • pp.273-279
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    • 2014
  • Purpose: This study assessed the association between eye symptoms (enophthalmos or diplopia) and site of damage, volume, deviated inferior rectus muscle (IRM) and type of fracture with computed tomography (CT). The intent is to anticipate the prognosis of orbital trauma at initial diagnosis. Methods: Forty-five patients were diagnosed with fractures of the inferior wall of one orbit. Fracture area, volume of displaced tissue, deviated IRM, and type of fracture were evaluated from coronal CT by one investigator. The association of those variables with the occurrence of eye symptoms (diplopia and enophthalmos) was assessed. Results: Of 45 patients, 27 were symptom-free (Group A) and 18 had symptoms (Group B) of enophthalmos and/or diplopia. In Group B, 12 had diplopia, one was enophthalmos, and five had both. By CT measurement, group A mean area was $192.6mm^2$ and the mean volume was $673.2mm^3$. Group B area was $316.2mm^2$ and volume was $1,710.6mm^3$. The volume was more influential on symptom occurrence. Each patient was categorized into four grades depending on the location of IRM. Symptom occurrence and higher grade were associated. Twenty-six patients had trap-door fracture (one side, attached to the fracture), and 19 had punched-out fracture (both sides detached). The punched-out fracture was more strongly associated with symptoms and had statistically significantly higher area and volume. Conclusion: In orbital trauma, measurement of fracture area and volume, evaluation of the deviated IRM and classification of the fracture type by coronal CT can effectively predict prognosis and surgical indication.

Job Analysis of the CHP Program in the Kangwon Area (강원도 보건진료원의 업무분석)

  • Kim, Sung-Sil
    • Research in Community and Public Health Nursing
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    • v.15 no.3
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    • pp.376-384
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    • 2004
  • Purpose: The CHP program has been evaluated as one of the most successful program in the public health area in Korea. The objects of this study were as follows: 1) to evaluate the job activities of the CHP program, using service contents analysis. 2) to figure out personal factors and the outcome of CHP's activities. Method: Data were collected by sending questionnaires to 130 subjects through the mail from May to December 2003. The response rate was 48.0%. The Data were analyzed by the SPSS WIN program with t test and Pearson correlation coefficient. In using these methods. independent variables are CHP's personal factors (age, experience, certification of specialty) and regional factors (geographical classification, aged population, village workers, cooperation of community leaders, work-conditions), and a dependent variable is the outcome of CHP's job activities. Result: The results of t test analysis show that regional differences between factors are influential in the welfare service, the routine job, and the consultation. As a whole, this is shown that CHPs represent experience, the number of village workers and CHPs living condition of work and most of the categories of jobs that influenced over statistical meaning of differences (t=2.417, p=1.043, t=6.123, p=.004, t=4.309, p=.000). There is a significant positive relation between the routine job and the consultation(r=.455, p=.000), the consultation and the education(r=.461, p=.000). Conclusion: Finally, according to the results of this study, the CHP program should be developed and continue to meet the basic health care needs of the residents in accordance with the philosophy of their own primary health care.

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Application of Regression Tree Model for the Estimation of Groundwater Use at the Agricultural (Dry-field Farming and Rice Farming) Purpose Wells (농업용(전작 및 답작용) 지하수 이용량 추정을 위한 회귀나무 모형의 적용)

  • Kim, yoo-Bum;Hwang, Chan-Ik
    • The Journal of Engineering Geology
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    • v.29 no.4
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    • pp.417-425
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    • 2019
  • Agricultural groundwater use accounts for 51.8% of total groundwater use, so accurate estimation of groundwater use is important for efficient groundwater management. The purpose of this study is to develop a method for estimating the groundwater use of agricultural (rice farming and dry-field farming) wells using regression tree model based on the measured data of 370 wells. Three input variables of the model were evaluated as being significant: well depth, pipe diameter, and pump capacity, and the importance of each variable was 75% for well depth, 17% for pipe diameter, and 8% for pumping capacity. The daily usage of agricultural (rice farming and dry-field farming) wells by the regression tree model was estimated to be very similar to the actual usage, compared to the previous estimation method proposed by the Ministry of Construction and Transportation. In the future, it is expected that the reliability of the usage statistics will be improved if additional observed data is secured and this classification method is modified.

Lateral Body Shapes of Males in Their 20s for the Development of Educational Dress Forms (Part 2)

  • Yoo, Hyun;Shim, Boo-Ja
    • Journal of Fashion Business
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    • v.9 no.3
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    • pp.47-63
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    • 2005
  • The study with the subjects at 200 adult males in Busan in their 20s had a purpose at analyzing lateral body shapes to develop men's educational dress forms. The following are the conclusions: 1. Comparison at the Body Dimensions at Busan Male Adults in Their 20s and the 5th Survey at Korean Body Measurement In the comparison at the Busan and national body dimensions by way at Mollison's relative deviation, all compared items were under the deviation of 0.7. Therefore, the sample of Busan male grown-ups is understood io represent the body shapes of the average Korean male adults in their 20s. 2. Results of Lateral Body Shape Classification From factor analysis, seven factors were produced to explain 75.45% of all variables. Those 7 factors to compose lateral body shapes were hip prominence, back-neck sides, upper body's front-back depth, lateral upper body depth, hip-waist depth, front chest-waist depth, and hip and waist height. Cluster analysis revealed four characteristic lateral body shapes. Type 1 with the appearance rate of 11.70%, named D, had the greatest upper chest angle and tanterior neck lower angle. The front side was more developed. Type 2 with 33.51%, named I, was generally long and slender. Type 3 with 24.47%, named d, had the biggest depth differences in hip-chest as well as more prominent back hip. Type 4 with 30.32%, named q, had the biggest dorsal upper angle and the tiniest chest upper angle as the back area was a little bent.

A Review of IOSS Design Standardization Technology for Aluminum Alloy Handrail of Offshore Platform

  • Kim, Yeon-Ho;Park, Joo-Shin;Shin, Hyun-Chang;Kim, Sung-Jun;Park, Dae-Kyeom;Ha, Yeon-Chul;Seo, Jung-Kwan
    • Journal of Ocean Engineering and Technology
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    • v.34 no.3
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    • pp.208-216
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    • 2020
  • The Integrated Offshore Standard Specification (IOSS) involves Korean shipyards, classification societies, research institutes, the Korean industrial society, engineering companies, and oil companies with the objective of reducing costs and risks without compromising safety in international offshore engineering procurement construction (EPC) projects using new standardized bulk components and qualification procedures. The activities of the IOSS include the analysis of the existing rules and regulations to achieve the best standardization, which is reflected in the best practices, and minimize the variables in regulations and rules. In addition, a standard inventory of shapes and dimensions, referred to as specifications, is proposed in the IOSS. In this paper, the aluminum tertiary standardization part (IOSS S102-1/2 S104: Specification for Structural Tertiary Design) is presented with the details of the procedures, background reviews, and cost-benefit analyses of the design and verification methods for standard designs in the IOSS standardization items. Based on the cost-benefit analysis, the application of standardized aluminum tertiary items to offshore projects has significant advantages in terms of maintenance and repair compared to the carbon steel tertiary items utilized in current industrial practices.