• Title/Summary/Keyword: Rank regression

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New Generation행s Consumer roles and Green Consumption Behavior (신세대 소비자의 역할수행 및 녹색소비행동)

  • 계선자
    • Journal of Family Resource Management and Policy Review
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    • v.3 no.1
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    • pp.1-15
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    • 1999
  • The purpose of this study is to find out the tendency of the new generation’s consumer roles and green consumption behavior for the environmental conservation. This study is also to reveal some fundamental information for an environmental education program which si able to support the new generation consumers to participate voluntarily in an environmental activity. The 500 subjects of this study were selected from the new generation consumers who wre residing in Seoul, 1998. The 414 data wre finally analyzed by Mean, t-Test, ANOVA, and Multiple Regression Analysis. The major findings were as follows: 1) the purchasing roles of the new generation consumer tended to be higher than the citizen participation’s roles. The variables with the higher score for the new generation’s green consumption behavior were in the rank of the isolation of environmental waste, the purchasing behavior of green product, the recycling environmental resource, and citizen’s participating roles in environmental activity. 2) the new generation’s consumer roles showed a significant differences, according to variables for the environmental value, environmental education, and participation of the environmental and societal activity 3) the green consumption behavior for the new generation consumers showed a significant differences, according to sex, environmental value, participation of the environmental and societal activity. 4) the most influential variables for the green consumption behavior of the new generation consumers were in the rank of consumer roles, educational values, and the participation of the environmental activity. As we see above, the consumer education for the new generations needs to focus on consumer’s roles that let them participate voluntarily in environmental and societal activity, as well as practice positively to use green environmental products whenever they select some items in the markets.

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Quality Assessment on Social Services in General and Teaching Hospitals in Korea (의료사회사업서비스의 질에 관한 연구)

  • Kang, Heung Gu
    • Quality Improvement in Health Care
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    • v.9 no.2
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    • pp.134-147
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    • 2002
  • Background : As an empirical study, current research about the quality of social services carried out in general and teaching hospitals across the country. In the flux of health care reforms and market transformation, the quality of social services in the hospital becomes increasingly significant. Methods : A sample of total 80 hospitals, including general hospitals with one social worker at least and single-department hospital with two social workers or more, were identified nationwide through the registry of Korean Association of Medical Social Workers and Korean Association of Hospitals. The subjects of this survey were 80 leaders of social service units. The survey data from each subjects were measured to evaluate level of quality that service provider perceived of sample hospitals. Under the method of one-way ANOVA and multiple regression, the level of quality in social work service was analyzed. Results : The major findings were as following ; First, the level of quality perceived showed less score, especially the lowest was the score of quality of outcome. Second, the key variables of each hospital which turned out significantly different in quality of social work service were the departmental form of social work unit, unit leader's age, educational level, field experience, and job rank. Third, the level of quality of social work service correlated positively with the field experience of unit leader, the size of social work unit, the job rank of the unit leader. Conclusion : The most influential variables to the quality of social work service proved departmental form of social work unit, leader of social work unit. Therefore, to assure the proper level of quality, social work unit in hospital must be structured single, independent department in which entitled social worker is supposed to supervise and manage. And a leadership-development program for leaders in social work unit are strongly recommended.

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Comparison of depression and oral health-related quality of life between the military personnel and public (군인과 일반인에서의 우울감과 구강건강관련 삶의 질 비교분석)

  • Kim, Myoung-Hee;Hwang, Young Sun;Kim, Tammy;Baek, Seol-Hwa;Lee, Ju-Hyun;Lee, Kyung-Ae
    • Journal of Korean Academy of Dental Administration
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    • v.7 no.1
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    • pp.29-38
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    • 2019
  • The goals of this study were to investigate depression and oral health-related quality of life in the military and public and to identify the factors affecting depression. The respondents were 278 soldiers and 228 general people of similar ages. An independent t-test was used to examine the differences between the two groups in the oral health impact profile and Self-rating Depression Scale. A multivariate logistic regression analysis was performed to examine the factors associated with depression in soldiers and the public. The depression level was significantly higher in the general population than in the military personnel (p<0.001). In contrast, the oral health-related quality of life was better in the general population than in the military, but without a statistical significance (p=0.056). Among soldiers, the military rank was the only factor associated with depression, showing a gradient based on the rank. In the general population, the type of work displayed significant associations with depression. As there are some limitations to investigating the factors affecting depression, comparative analyses of the general population groups with similar soldier groups are rare. This study encourages future investigations of the advancements in mental health and improvement programs for oral health in each group.

Machine Learning Model for Recommending Products and Estimating Sales Prices of Reverse Direct Purchase (역직구 상품 추천 및 판매가 추정을 위한 머신러닝 모델)

  • Kyu Ik Kim;Berdibayev Yergali;Soo Hyung Kim;Jin Suk Kim
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.46 no.2
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    • pp.176-182
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    • 2023
  • With about 80% of the global economy expected to shift to the global market by 2030, exports of reverse direct purchase products, in which foreign consumers purchase products from online shopping malls in Korea, are growing 55% annually. As of 2021, sales of reverse direct purchases in South Korea increased 50.6% from the previous year, surpassing 40 million. In order for domestic SMEs(Small and medium sized enterprises) to enter overseas markets, it is important to come up with export strategies based on various market analysis information, but for domestic small and medium-sized sellers, entry barriers are high, such as lack of information on overseas markets and difficulty in selecting local preferred products and determining competitive sales prices. This study develops an AI-based product recommendation and sales price estimation model to collect and analyze global shopping malls and product trends to provide marketing information that presents promising and appropriate product sales prices to small and medium-sized sellers who have difficulty collecting global market information. The product recommendation model is based on the LTR (Learning To Rank) methodology. As a result of comparing performance with nDCG, the Pair-wise-based XGBoost-LambdaMART Model was measured to be excellent. The sales price estimation model uses a regression algorithm. According to the R-Squared value, the Light Gradient Boosting Machine performs best in this model.

Prognostic Value of Artificial Intelligence-Driven, Computed Tomography-Based, Volumetric Assessment of the Volume and Density of Muscle in Patients With Colon Cancer

  • Minsung Kim;Sang Min Lee;Il Tae Son;Taeyong Park;Bo Young Oh
    • Korean Journal of Radiology
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    • v.24 no.9
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    • pp.849-859
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    • 2023
  • Objective: The prognostic value of the volume and density of skeletal muscles in the abdominal waist of patients with colon cancer remains unclear. This study aimed to investigate the association between the automated computed tomography (CT)-based volume and density of the muscle in the abdominal waist and survival outcomes in patients with colon cancer. Materials and Methods: We retrospectively evaluated 474 patients with colon cancer who underwent surgery with curative intent between January 2010 and October 2017. Volumetric skeletal muscle index and muscular density were measured at the abdominal waist using artificial intelligence (AI)-based volumetric segmentation of body composition on preoperative pre-contrast CT images. Patients were grouped based on their skeletal muscle index (sarcopenia vs. not) and muscular density (myosteatosis vs. not) values and combinations (normal, sarcopenia alone, myosteatosis alone, and combined sarcopenia and myosteatosis). Postsurgical disease-free survival (DFS) and overall survival (OS) were analyzed using univariable and multivariable analyses, including multivariable Cox proportional hazard regression. Results: Univariable analysis showed that DFS and OS were significantly worse for the sarcopenia group than for the non-sarcopenia group (P = 0.044 and P = 0.003, respectively, by log-rank test) and for the myosteatosis group than for the non-myosteatosis group (P < 0.001 by log-rank test for all). In the multivariable analysis, the myosteatotic muscle type was associated with worse DFS (adjusted hazard ratio [aHR], 1.89 [95% confidence interval, 1.25-2.86]; P = 0.003) and OS (aHR, 1.90 [95% confidence interval, 1.84-3.04]; P = 0.008) than the normal muscle type. The combined muscle type showed worse OS than the normal muscle type (aHR, 1.95 [95% confidence interval, 1.08-3.54]; P = 0.027). Conclusion: Preoperative volumetric sarcopenia and myosteatosis, automatically assessed from pre-contrast CT scans using AI-based software, adversely affect survival outcomes in patients with colon cancer.

Prognostic Factors of Malignant Pleural Effusion in Non-small Cell Lung Cancer (비소세포폐암에 발생한 악성 흉수의 예후 인자)

  • Lim, Chang-Young;Lee, Gun;Lee, Hyeon-Jae
    • Journal of Chest Surgery
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    • v.40 no.2 s.271
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    • pp.109-113
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    • 2007
  • Background: In non-small cell lung cancer (NSCLC), malignant pleural effusion is a frequently observed com-plication, and is an important negative prognostic factor. Although many studies concerned to diagnosis and treatment of malignant pleural effusion have been performed, prognostic factors of malignant pleural effusion have rarely been investigated. This study was performed to determine the prognostic factors of malignant pleural effusion n non-small cell lung cancer. Material and Method: We evaluated 33 NSCLC patients with malignant effusion treated between January 2002 and December 2003. We analyzed possible factors: gender, age, TNM Stage, fluid analysis (pH, CEA, LDH, glucose, albumin) and treatment modality. Median survival time of each factor was calculated by Kaplan-Meier method and difference of median survival time between groups of factor compared by log-rank test. The Cox proportional hazards regression model was used to confirm the significance of prognostic factor. Results: Of the 33 patients, 23 (69.7%) patients were adenocarcinoma. The median interval of the diagnosis of lung cancer and malignant effusion was 7.3 months ($25^{th}{\sim}75^{th}:\;3.9{\sim}11.8$), and the median survival time was 3.6 months (95% Confidence Interval: $1.14{\sim}5.99$). In the univariate analysis, using the log-rank test, those with an adenocarcinoma showed a relatively longer median survival time than those of a non-adenocarcinoma (4.067 vs. 1.867 months, p=0.067) without statistical significance. In the multivariate analysis, using the Cox regression, those with a non-adenocarcinoma showed a trend of high risk of cancer death than those with an adenocarcinoma without statistical significance (Relative risk; 2.754, 95% Cl: $0.988{\sim}7.672$, p=0.053). Conclusion: We could not find an independent prognostic factor of malignant pleural effusion in NSCLC. As there was a trend of high risk of cancer death according to histology, further study will be needed.

Prognostic Value of Serum Ferritin in Terminally Ill Cancer Patients (말기암환자에서 예후인자로서 혈청 Ferritin의 유용성)

  • Lee, Soo Hee;Choi, Youn Seon;Hwang, In Cheol;Yeom, Chang Hwan;Lee, June Yeong
    • Journal of Hospice and Palliative Care
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    • v.18 no.1
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    • pp.51-59
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    • 2015
  • Purpose: Predicting life expectancy of terminally ill cancer patients is very important. In many studies, ferritin is detected at higher levels in the sera of cancer patients, and higher ferritin level correlates with aggressiveness of disease and poor outcomes of patients. This study evaluated a prognostic role of serum ferritin levels in terminally ill cancer patients. Methods: This study enrolled 65 terminally ill cancer patients from March through June 2012. We assessed routine laboratory findings including serum ferritin levels as well as demographic and clinical characteristics of the patients. To examine the association between serum ferritin levels and patient's characteristics, we used Spearman's correlation analysis, Wilcoxon's rank sum test or Kruskal-Wallis test, as appropriately. For multivariate analysis, Cox's proportional hazard regression model was used to evaluate significance of serum ferritin levels as a prognostic factor. Results: A negative correlation between serum ferritin levels and survival time was found. After adjusting for sex, age, performance status, creatinine levels and white blood cell counts, serum ferritin levels were significantly associated with survival time. Conclusion: Even at the very end of life of terminal cancer patients, serum ferritin levels were an independent prognostic factor for survival.

Trend and Shift Analysis for Hydrologic and Climate Series (수문 및 기후 자료에 대한 선형 경향성 및 평균이동 분석)

  • Oh, Je Seung;Kim, Hung Soo;Seo, Byung Ha
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.4B
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    • pp.355-362
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    • 2006
  • Several techniques of MK test, Spearman's Rho test, Linear Regression test, CUSUM test, Cumulative Deviation, Worsley Likelihood Ratio test, Rank Sum test, and Students' t test were applied to detect the trends of slope and shift which exist in hydrologic and climate time series. The time series of annual rainfall, inflow, tree ring index, and southern oscillation index (SOI) were used and the trends of these series were compared in the study. From the results, it can be found that the data could be classified into two categories such as linear trend and shift. 4 series data of 8 rainfall series which reveal the trend show the shift and 8 series data of 18 tree ring index and March and April series of monthly SOI data show shift. Moreover, ADF test and BDS test were used to test stationarity and non-linearity of the data. In conclusion, through the study, various trend analysis techniques were compared and 6 kinds of characteristics which can exist in hydrologic time series were identified.

No-Touch vs. Conventional Radiofrequency Ablation Using Twin Internally Cooled Wet Electrodes for Small Hepatocellular Carcinomas: A Randomized Prospective Comparative Study

  • Yun Seok Suh;Jae Won Choi;Jeong Hee Yoon;Dong Ho Lee;Yoon Jun Kim;Jeong Hoon Lee;Su Jong Yu;Eun Ju Cho;Jung Hwan Yoon;Jeong Min Lee
    • Korean Journal of Radiology
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    • v.22 no.12
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    • pp.1974-1984
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    • 2021
  • Objective: This study aimed to compare the efficacy between no-touch (NT) radiofrequency ablation (RFA) and conventional RFA using twin internally cooled wet (TICW) electrodes in the bipolar mode for the treatment of small hepatocellular carcinomas (HCC). Materials and Methods: In this single-center, two-arm, parallel-group, prospective randomized controlled study, we performed a 1:1 random allocation of eligible patients with HCCs to receive NT-RFA or conventional RFA between October 2016 and September 2018. The primary endpoint was the cumulative local tumor progression (LTP) rate after RFA. Secondary endpoints included technical conversion rates of NT-RFA, intrahepatic distance recurrence, extrahepatic metastasis, technical parameters, technical efficacy, and rates of complications. Cumulative LTP rates were analyzed using Kaplan-Meier analysis and the Cox proportional hazard regression model. Considering conversion cases from NT-RFA to conventional RFA, intention-to-treat and as-treated analyses were performed. Results: Enrolled patients were randomly assigned to the NT-RFA group (37 patients with 38 HCCs) or the conventional RFA group (36 patients with 38 HCCs). Among the NT-RFA group patients, conversion to conventional RFA occurred in four patients (10.8%, 4/37). According to intention-to-treat analysis, both 1- and 3-year cumulative LTP rates were 5.6%, in the NT-RFA group, and they were 11.8% and 21.3%, respectively, in the conventional RFA group (p = 0.073, log-rank). In the as-treated analysis, LTP rates at 1 year and 3 years were 0% and 0%, respectively, in the NT-RFA group sand 15.6% and 24.5%, respectively, in the conventional RFA group (p = 0.004, log-rank). In as-treated analysis using multivariable Cox regression analysis, RFA type was the only significant predictive factor for LTP (hazard ratio = 0.061 with conventional RFA as the reference, 95% confidence interval = 0.000-0.497; p = 0.004). There were no significant differences in the procedure characteristics between the two groups. No procedure-related deaths or major complications were observed. Conclusion: NT-RFA using TICW electrodes in bipolar mode demonstrated significantly lower cumulative LTP rates than conventional RFA for small HCCs, which warrants a larger study for further confirmation.

Uncertainty and Sensitivity Analysis of Time-Dependent Deformation in Prestressed Concrete Box Girder Bridges (프리스트레스트 콘크리트 박스 거더 교량의 시간에 따른 변형의 확률 해석 및 민감도 해석)

  • 오병환;양인환
    • Magazine of the Korea Concrete Institute
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    • v.10 no.6
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    • pp.149-159
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    • 1998
  • The reasonable prediction of time-dependent deformation of prestressed concrete(PSC) box girder bridges is very important for accurate construction as well as good serviceability. The long-term behavior is mostly influenced by the probabilistic characteristic of creep and shrinkage. This paper presents a method of statistical analysis and sensitivity analysis of creep and shrinkage effects in PSC box been taken into account - model uncertainty, parameter variation and environmental condition. The statistical and sensitivity analyses are performed by using the numerical simulation of Latin Hypercube sampling. For each sample, the time-dependent structural analysis is performed to produce response data, which are then statistically analyzed. The probabilistic prediction of the confidence limits on long-term effects of creep and shrinkage is then expressed. Three measure are examined to quantify the sensitivity of the outputs of each of the input variables. These are rank correlation coefficient(RCC), partical rank correlation coefficient(PRCC) and standardiozed rank regression coefficient(SRRC) computed on the ranks of the observations. Three creep and shrinkage models - i. e., ACI model. CEB-FIP model and the model in Korea Highway Bridge Specification - are studied. The creep model uncertainy factor and the relative humidity appear to be the most dominant factors with regard to the model output uncertainty.