• Title/Summary/Keyword: regression factor

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A Study on The Virtuous Cycle of The Value Chain and Value System in Korean Photovoltaic Industry (한국 태양광산업의 가치사슬과 가치시스템 선순환 구조 분석)

  • Park, Sung-Hwan;Park, Min-Hyug;Park, Jung-Gu
    • Journal of Energy Engineering
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    • v.23 no.1
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    • pp.21-32
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    • 2014
  • This study has analyzed whether the virtuous cycle of value-added between the processes within the company has formed and whether the virtuous ecosystem between the processes within the industry has been built through the analysis of value chain(VC) and value system(VS) targeting the Korean photovoltaic companies. For a study method, after conducting a survey on the companies, a regression analysis was performed on the causal relationship between the process within the VC and VS. Based on the results of the analysis, for the VC of the Korean photovoltaic industry, an increase in the R&D support from the government has led to the increase in the investment of R&D for the related industry, and the increase in the investment of R&D has contributed to the increase in the growth of its productivity, and the growth in the productivity of R&D has influenced the increase in the production of solar products. In addition, the reduction of photovoltaic production cost for the company has influenced the increase of recurring profit margin compared to the sales. However it was shown that the increase in the company's production volume does not contribute to the reduction of production cost. Meanwhile, the increase in recurring profit margin compared to the sales were influencing the increase in the production volume but it was shown that the increase in the company's investment of R&D was not a contributing factor thus it was not included in the virtuous cycle. It was analyzed that the VS was shown not to influence all other processes within the industry except for the module companies where the increase in the recurring profit margin compared to the sales was influenced by the increase in the recurring profit margin compared to the sales of solar cell companies. This shows that the virtuous industrial ecosystem which should be made under the mutual cooperation by the ingot, wafer, solar cell, module and system companies are yet incomplete.

Prediction of Life-expectancy for Patients with Hepatocellular Carcinoma Based on Prognostic Factors (간암 환자에서 예후인자를 통한 생존기간의 예측)

  • Yeom, Chang-Hwan;Shim, Jae-Yong;Lee, Hye-Ree;Hong, Young-Sun
    • Journal of Hospice and Palliative Care
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    • v.1 no.1
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    • pp.30-38
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    • 1998
  • Background : Hepatocellular carcinomoma is the 3rd most common malignancy and the 2nd most common cause of death in Korea. The prediction of life-expectancy in terminal cancer patients is a major problem for patients, families, and physicians. We would like to investigate the prognostic factors of hepatocellular carcinoma, and therefore contribute to the prediction of the survival time of patients with hepatocellular carcinoma. Methods : A total of 91 patients(male 73, female 18) with hepatocellular carcinoma who were admitted to the hospital between January and lune 1995 were entered into the study, and data were collected prospectively on 28 clinical parameters through medical obligation record. We surveyed an obligation and local district office records, and confirmed the surivival of patients till July, 1996. Using Cox-proportional hazard model, give the significant variables related to survival. These determined prognostic factors. Life regressional analysis was used, there were calculated predicted survival day based on combinations of the significant prognostic factors. Results : 1) Out of 91 patients, 73 were male, and 18 were female. The mean age was $56.7{\pm}10.6$ ears. During the study, except for 16 patients who could not follow up, out of 75 patients, the number of deaths was 57(76%) and the number of survivals was 18(24%). 2) Out of the 28 clinical parameters, the prognostic factors related to reduced survival rate were prothrombin time<40%(relative risk:10.8), weight loss(RR:4.4), past history of hypertension (RR:3.2), ascites(RR:2.8), hypocalcemia(RR:2.5)(P<0.001). 3) Out of five factors, the survival day is 1.7 in all of five, $4.2{\sim}10.0$ in four, $10.4{\sim}41.9$ in three, $29.5{\sim}118.1$ in two, $124.0{\sim}296.6$ in one, 724.0 in none. Conclusion : In hepatocellular carcinoma we found that the prognostic factors related to reduce survival rate were prolonged prothrombin time(<40%), weight loss, past history of hypertension, ascites, and hypocalcemia(<8.7mg/dl). The five prognostic factors enabled the prediction of life-expectancy in patients with hepatocellular carcinoma and may assist in managing patients with hepatocellular carcinomal.

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Environmental Studies in the Lower Part of the Han River Vl. The Statistical Analysis of Eutrophication Factors (한강 하류의 환경학적 연구 Vl. 부영양 요인의 통계적 해석)

  • Jung, Seung-Won;Hue, Hoi-Kwon;Lee, Jin-Hwan
    • Korean Journal of Ecology and Environment
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    • v.37 no.1 s.106
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    • pp.78-86
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    • 2004
  • In order to reveal the relationship between the concentration of chlorophyll- a and the environmental factors affecting eutrophication, the present study was biweekly conducted at G stations in the lower part of the Han river during the period from Feb. 24,2001 to Feb. 9,2002. Water temperature was changed from $0.5^{\circ}C$ to $26.4^{\circ}C$, pH was 5.77${\sim}$8.99, DO 3.15${\sim}$14,36 mg $L^{-1}$, BOD 0.90${\sim}$7.45 mg $L^{-1}$, and COD 1.16${\sim}$9.13 mg $L^{-1}$. TN and TP were ranged from 1.68${\sim}$20.96 mg $L^{-1}$, and 0.02 ${\sim}$ 1.17 mg $L^{-1}$, respectively. $NH_4\;^+$-N, $NO_3\;^-$-N, and $PO_4\;^{3-}$-P were ranged from 0.56${\sim}$3.60 mg $L^{-1}$, 0.03${\sim}$7.29 mg $L^{-1}$, and 0.002${\sim}$0.754 mg $L^{-1}$. Chlorophyll- a was extensively changed from 2.29 ${\mu}g\;L^{-1}$ to 136.28 ${\mu}g\;L^{-1}$ by month and stations. Results of nutrients indicated the eutrophic level in this area and water quality was the gradual worsening in the lower stations than those of upper stations during the period studied. The Pearson correlation analysis between the concentration of chlorophyll- a and the environmental factors indicated that BOD, COD, pH, $NH_4\;^+$-N, TP, TN, conductivity and $PO_4\;^{3-}$-P were positive correlation, but $NO_3\;^-$-N was negative. The environmental factors investigated using the principal component method could be triparted. The first factor group included conductivity, BOD, COD, TN, TP, $NH_4\;^+$-N, $PO_4\;^{3-}$-P and SS, the second WT and DO, and the third pH and $NO_3\;^-$-N. Using the stepwise regression analysis, chlorophyll- a was under the influence of conductivity, $PO_4\;^{3-}$-P, $>NO_3\;^-$-N and $NH_4\;^+$-N Chlorophyll-a = 0.3661 ${\times}$ (Conductivity) - 0.3592 ${\times}$ ($PO_4\;^{3-}$-P) - 0.3449 ${\times}$ ($NO_3\;^-$-N)+0.4362 ${\times}$ ($NH_4\;^+$-N.

Relation between Chemical Properties of Soil and Tree Growth (토양(土壤)의 화학적(化學的) 성질(性質)과 임목생장(林木生長)과의 관계(關係))

  • Chung, Young Gwan;Hong, Byung Wha;Kim, Jong Man
    • Journal of Korean Society of Forest Science
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    • v.46 no.1
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    • pp.10-20
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    • 1980
  • This experiment was carried out to investigate the effects of physico-chemical properties of soil on the growth of Chamaecyparis obtusa and to apply the results to such rational forest management as yield forecast and selection of suitable species for a given forest stand. The soil properties observed in this experiment were soil pH, exchangeable pH organic matter, total nitrogen, available $P_2O_5$, cation exchange capacity, exchangeable $H^+$, total base and base saturation. Diameter at breast height (DBH), height and volume growth of C. obtusa were observed at 78 sampling sites. Data were processed into the following series for the analysis of multivariates : inner correlation matrix, multiple correlation coefficients, regression coefficients and partial correlation coefficients. The results are summerized as follows : 1. Multiple correlation coefficients between soil properties and DBH of C. obtusa were .364 for 20-year trees, resulting less efficient for estimating the growth of C. obtusa. However, total base, soil pH and base saturation were considerable characters for better estimation. 2. More efficient multiple correlation coefficients were observed between soil properties and height growth than those between soil properties and DBH, showing .443 for 20-year trees and factors affecting the height growth were similar to those of DBH. 3. Extremely low values of multiple correlation coefficients were estimated between physico-chemical properties of soil and volume growth of C. obtusa resulting low efficient estimation. However, total base contributed highly to volume growth of C. obtusa. Accordingly the most contributable factor for estimating the growth of C. obtusa were total base, soil pH and base saturation. Consequently, these results can be effective for selecting of the reforesting site, and less effective for estimating the growth of C. obtusa.

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Oral Hygiene Management and Factor Analysis of the Community People (일부지역 주민들의 구강환경관리 및 요인분석)

  • Park, Hyang-Sook;Kim, Jin-Soo;Kim, Jin-Mi;Kim, Yoon-Sin
    • Journal of dental hygiene science
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    • v.10 no.1
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    • pp.11-16
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    • 2010
  • The subjects of this study were patients at scaling practice, the total number of the subjects was 249 of 138 men and 111 women. The results were analyzed using SPSS 12.0. 1. In oral health care, among tooth brushing methods, scrub method was found to be 65.9%(164 patients), and 83.9%(209 patients) did not use oral care aids. 2. Mean calculus index was $0.57{\pm}0.22$. 3. For calculus index per tooth brushing method, there was statistically significant difference in all of the upper jaw, the lower jaw, the anterior portion, and the posterior portion(p < 0.05). 4. For calculus index per frequency of tooth brushing, there was statistically significant difference in the upper jaw, the lower jaw, and the posterior portion(p < 0.05). 5. For calculus index per time of tooth brushing and per use of oral care aids, there was statistically significant difference in all of the upper jaw, the lower jaw, the anterior portion, and the posterior portion(p < 0.05). 6. For factors influencing calculus index, as a result of applying stepwise method based on 0.05 of significance level, age, use of oral care aids, sex, and time of tooth brushing were found to influence calculus index. Final regression model was calculus index = $0.362^*age+0.216^*$use of oral care aids - $0.161*sex-0.127^*$time of tooth brushing, and explanatory power of the model was 23.4%. $0.362^*age+0.216^*$use of oral care aids - $0.161^*sex-0.127^*$time of tooth brushing, and explanatory power of the model was 23.4%.

Comparison of the Awareness and Knowledge of Scrub Typhus between Case and Control Groups (쯔쯔가무시증 환자군과 대조군의 인지도와 지식 비교)

  • Lee, Kwan;Park, Byeong-Chan;Lim, Hyun-Sul;Kweon, Sun-Seog;Choi, Jin-Su;Kim, Jang-Rak;Kim, Keon-Yeop;Ryu, So-Yeon
    • Journal of agricultural medicine and community health
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    • v.37 no.1
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    • pp.1-11
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    • 2012
  • Objectives: To survey the awareness of patient to scrub typhus to provide data for education and communication concerning scrub typhus. Methods: Patients with scrub typhus (case group, n=299) and people without scrub typhus within the previous 2 years (control group, n=598) were matched for age (within 5 years), gender, and occupation (farmer or non-farmer). The participants were recruited from 15 study areas between October and December 2006. Results: The awareness rate of scrub typhus was 75.1%, and was significantly higher than in the case group (79.4% vs. 66.6%, respectively; p<0.01). The major routes of awareness were from 'past history of scrub typhus in family members or neighbors' (54.9%), 'television' (28.3%), and their past history of scrub typhus (5.5%). The average correct rate of scrub typhus was 48.4%, and the correct response rate of cases was significantly higher than controls (p<0.01). Especially, the correct rate of etiology, incubation period, route of transmission, and acquired immunity was <40%. Through conditional logistic regression test, the factor significantly associated with awareness in case group was age (odds ratio [OR], 0.96; 95% confidence interval [CI], 0.94-0.98). And the factors associated with awareness in control group were female (OR, 1.56; 95% CI, 1.03-2.36) age (OR, 0.98; 95% CI, 0.96-0.99), family history of scrub typhus (OR, 10.18; 95% CI, 1.37-75.99), history of receiving prevention education (OR, 8.47; 95% CI, 1.14-63.00). Conclusions: The rate of awareness was relatively low in study population. Thus, effective working guidelines and educational program to prevent scrub typhus must be developed, and publicity activities about the prevention of scrub typhus are needed for high-risk groups.

Awareness and Need as Factors in an Incremental Oral Health Care Program for Korean Adults (일부 성인의 계속구강관리프로그램 인식과 요구도)

  • Jang, Ho-Yeol;Lee, Su-Ryeon;Lee, Yun-Ji;Lee, Soo-Bin;Lee, Ha-Neul;Lee, Hye-Bin;Hwang, Soo-Jeong
    • Journal of dental hygiene science
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    • v.16 no.6
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    • pp.442-448
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    • 2016
  • Dental caries and periodontal disease are considered to be chronic, but can be prevented through an incremental oral health program covering all ages. The National Oral Health Program for adults provides oral health exam and scaling, and is covered by national health insurance for those over 20 years of age in Korea. The aim of this study was to collect basic data for developing an oral health program for adults by identifying factors related to awareness and need. The data were obtained by convenience sampling of 303 subjects. The use of dental plaque disclosing agents affected tooth brushing frequency, toothbrushing time and use of oral auxiliary devices. Education on toothbrushing methods affected toothbrushing time and use of oral auxiliary devices. Of those surveyed, 93.1% replied that an incremental oral health program for adults was needed, and 68.0% intended to participate. In a regression model, the factors that had an effect on the perceived need for an oral health program were education level, use of oral hygiene auxiliary devices, and toothbrushing time, and the factors affecting intent to participate were education for prevention of periodontal disease and the use of oral hygiene auxiliary devices. The subjects stated that the following oral health programs were needed: an oral bacteria exam (74.3%), toothbrushing education (71.6%), a bad breath exam (69.3%), education on use of oral hygiene auxiliary devices (46.9%), a dental plaque exam (42.9%) and a saliva exam (37.6%). Oral health education appears to be an important factor for participation in an incremental oral health program.

Ionic composition and pollution characteristics of precipitation in Jeju Island during 2009-2014 (2009-2014년 제주지역 강수의 이온조성 및 오염특성)

  • Bu, Jun Oh;Song, Jung Min;Shin, Su Hyun;Kim, Won Hyung;Kang, Chang Hee
    • Analytical Science and Technology
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    • v.29 no.1
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    • pp.19-28
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    • 2016
  • The objective of this study was to determine the acidification of precipitation in the Jeju area. Precipitation samples were collected from the Jeju area from 2009-2014, and the major ionic species were analyzed. In the regression analysis, through a comparison of ion balance, electric conductivity, and acid fraction, the correlation coefficients showed a good linear relationship within the range of 0.927~0.983. The volume-weighted means of the pH and electric conductivity were 4.9 and 22.7 µS/cm, respectively. The ionic strength of precipitation was 0.27±0.38 mM, indicating about 35.9 % of total precipitation within the pure precipitation criteria. The volume-weighted mean concentrations (ìeq/L) of the ionic species in the precipitation were in the order of Na+ > Cl > nss-SO42− > NO3 > NH4+ > Mg2+ > H+ > nss-Ca2+ > PO43− > K+ > HCOO > CH3COO > NO2 > F > HCO3 > CH3SO3 . The acidification contributions by sulfuric and nitric acids were 54.5 % and 36.5 %, respectively. Meanwhile the acidification contributions by formic and acetic acids were 4.8 % and 4.2 %, respectively. Thus, it was found that the acidification of the precipitation in the Jeju area was mainly due to the inorganic acids. The neutralization factors by NH3 and CaCO3 were also 33 % and 20 %, respectively.

Analysis of Sustainable Management Factors in County Parks Based on the Sustainability Evaluation Framework of Korea Nature Parks - Focus on the 11 County Parks in Gyeongsangnam-do - (자연공원 지속가능성평가에 기반한 군립공원 지속가능성 영향요인 분석 - 경남권역 11개소 군립공원을 대상으로 -)

  • Hong, Sukhwan;Ahn, Rosa;Tian, Wanting;Heo, Hagyoung;Pak, Junhou
    • Journal of the Korean Institute of Landscape Architecture
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    • v.48 no.3
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    • pp.12-21
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    • 2020
  • This study aims to implement the Sustainability Evaluation Framework of Korea Natural Parks to county parks in Gyeongsangnam-do, and to review the performance status of management effectiveness evaluation (MEE) and identify factors that influence the improvement of management effectiveness in protected areas. County park officers evaluated current management using this framework that was developed based on the MEE framework designed by the Korean Ministry of Environment. Among the principal values of county parks, 'natural and ecological' is indicated as the most important, followed by 'cultural and historic value' and 'leisure and recreation'. Natural disasters and climate change, visitor impact-inappropriate visitor behavior are indicated as current threats, and three county parks administrators viewed that there was no particular threat to their park. According to MEE results, the most effective management fields were 'State of cultural and historic value', 'State of leisure and recreational value', 'Current state of principal value'. The comparatively weaker fields were 'Threatened species management', 'Invasive species management', 'Management monitoring and evaluation'. The effects of sustainable management on county parks were analyzed through a regression analysis, and the influence of management factors reveal 'Annual budget', will impact attaining higher management scores. This study presents the current management information about county parks and provides support for the basis for the planning of county parks in Korea, suggesting the influencing factor.

Prevalence and Risk Factors of Gallstones in Adult Health Screening Population (건강한 성인의 담석 유병률과 위험인자)

  • Lee, Mi-Hwa;Kwon, Duck-Moon;Cho, Pyong-Kon
    • Journal of radiological science and technology
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    • v.37 no.4
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    • pp.287-294
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    • 2014
  • Gallstone is the most common disease of the biliary system. Korean has experienced an increase in the percentage of cholesterol gallstones. The major risk factors associated with cholesterol gallstones are age, gender as well as obesity. This study was designed to determine the prevalence of gallstones in the last three years and evaluate the associated risk factors in the population who underwent health screening. The study population consisted of 2,484 males and 2,212 females who visited the health promotion center in Dalseogu, Daegu in Korea from January 2011 to December 2013. Each participant in the study had their biliary system gallbladder examined using ultrasonography. Classified as underweight, normal weight or overweight using the population of obese according to the body mass index, and classified according to mood diagnosis of diabetes presented by the American Diabetes Association. Fasting blood glucose and number of liver function, the divided the control group by referring to the normal liver function values used herein. The geological map, I was classified as NCEP APT III. A showed of total 148 people were found to have gallstones. The prevalence of sex among 148 patients (3.15%) 84 men (1.79%) and 64 women 1.36%) which shows significantly there is little difference. 1.84% 40 years and below, 3.38% 40's showed age prevalence was 4.66% in 50's and above. In addition, Total-cholesterol was at the most in 52 people, LDL-cholesterol in 398 people, Triglyceride in 36 people, HDL-cholesterol in 19 people. The abnormal group, was created from the total-cholesterol categories from a physical examination of a subject that has been found to be gallstones in the gallbladder. A result of conducting the univariate analysis shows the prevalence of gallstones, a correlation that is meaningful. The logistic regression analysis of multiple ages was chosen to show risk factors age independent cholelithiasis. In spite of the conclusion, gallstones are not displayed in relation to the metabolic syndrome but in order to clarify this, not only the subject of a health examination is needed but, a further study of the general public when possible.