• Title/Summary/Keyword: model predictive

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A Comparative Study on the Methods for Weighting the Dimensions of Customer Satisfaction with Importance Perceived by Customers (고객만족도 조사도구의 차원별 가중치 부여방법 비교)

  • Kang, Myunggeun;Cho, Woohyun;Lee, Sunhee;Choi, Kuison;Mooon, Kitae
    • Quality Improvement in Health Care
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    • v.7 no.2
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    • pp.230-242
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    • 2000
  • Background : The measuring instruments for customer satisfaction in hospitals are often composed of some dimensions reflecting the conceptive complexity of them. Then, overall satisfaction would be expected to be equal the 'weighted' sum of scores by dimensions because the importance rated by customers may be different across the dimensions. But the issue of how to weight the dimensions with importance is not yet solved. We examined 3 sets of weighting methods as to make effect on predictive power against overall satisfaction. Methods : We conducted a survey included 483 subjects who had visited or admitted to a university hospital, using the short form questionnaire being developed by The Korean Society of Quality Assurance in Health Care for out-patient and in-patient. By using a multiple linear regression model, we compared among changes of explanatory powers against overall satisfaction as dependent variable after weighting 4 dimensions of the survey questionnaire as independent variables with importance scores of dimensions perceived by consumers. And we compared the feasibility of each weighting, methods by checking missing cases. Results : There were no weighting methods increasing the explanatory power after applying them. The method of absolute scoring was found higher explanatory-power than others, but this finding had no statistical significance. Regarding the number of missing value, method of absolutely scoring had the least cases. Conclusion : Our findings suggested that weighting the dimensions with importance might have little significance in the cases of scales having items highly correlated, such as consumers' satisfaction. Though asking with items to be answered absolutely, customers might be rating relatively in some degree and this method produced least missing cases. Considering these points, in the cases when weighting the dimensions with importance would be required, we suggest that weighting method by absolute scoring might be better than others.

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A Study on Factors of Management of Diabetes Mellitus using Data Mining (데이터 마이닝을 이용한 당뇨환자의 관리요인에 관한 연구)

  • Kim, Yoo-Mi;Chang, Dong-Min;Kim, Sung-Soo;Park, Il-Su;Kang, Sung-Hong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.5
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    • pp.1100-1108
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    • 2009
  • The Objectives: The purpose of this study is to identify the factors related to management of DM in Korea. Methods: The subjects selected by using data of National Health and Nutrition Survey(NHANS) in 2005 were 415 adults, aged 20 and older, and diagnosed with DM. This study used data mining algorithms. This study validated the predictive power of data mining algorithms by comparing the performance of logistic regression, decision tree, and Neural Network on the basic of validation, it was found that the model performance of decision tree was the best among the above three techniques. Result: First, awareness of DM was positively associated with age, residential area, and job. The most important factor of DM awareness is age. Awareness rate of DM with 52 age over is 76.1%. Among the ${\geq}52$ age group, an important factor is family history. Among patients who are 52 years or over with family history of DM, an important factor is job. The awareness rate of patients who are 52 age over, family, history of DM, and professionals is 95.0%. Second, treatment of DM was also positively associated with awareness, region, and job. The most important factor of DM treatment is DM awareness. Treatment rate of patients who are aware of DM is 84.8%. Among patients who have awareness of DM, an important factor is region. The awareness rate of patients who are aware of DM in rural area is 10.4%. Conclusion: Finally, the result of analysis suggest that DM management programs should consider group characteristic of DM patients.

Occurrence and Survival Rate of the Larvae of Sea Mussel, Mytilus edulis (담치 종묘생산기술개발에 관한 연구 -진주담치 Mytilus edulis 부유유생의 출현과 생존율)

  • YOO Sung Kyoo;KANG Kyoung Ho;LEE Dong Yeub
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.21 no.1
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    • pp.35-41
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    • 1988
  • In order to set up a predictive model for effective spat collection of sea mussel Mytilus edulis , the survival rate and time required at each developmental stage of drifting larvae were surveyed during the period from March 14 to July 20 in 1987 at the Naesan Ri, Jinhae Bay, the southern part of Korea. The advent of D - shape larvae ca. $120\times90um$ um long had three peaks in that area: April 15, May 13 and June 7. Umbo shape larvae ca.$188\times162{\mu}m$ and full grown larvae ca. $289\times280{\mu}m$ long also showed three peaks: April 27. May 24 and June 20 for the former, and May 10, June 5 and June 30 for the latter. Eleven to thirteen days were required for D - shape larvae to develop to umbo - shape larvae. The instantaneous death rate was 0.1300 and the daily survival rate 0.8781 at this intermorphological stage. The turnover time of umbo to full grown larvae varied from ten to thirteen days with a instantaneous death rate of 0.1520, daily survival rate of 0.8590, and mean survival rate of $16.89\%$. Twenty - three to twenty - five days were required for each group of the D - shape larvae to reach a full grown stage, and their mean survival rate was $3.55\%$ during this developmental period.

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Audio Stream Delivery Using AMR(Adaptive Multi-Rate) Coder with Forward Error Correction in the Internet (인터넷 환경에서 FEC 기능이 추가된 AMR음성 부호화기를 이용한 오디오 스트림 전송)

  • 김은중;이인성
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.26 no.12A
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    • pp.2027-2035
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    • 2001
  • In this paper, we present an audio stream delivery using the AMR (Adaptive Multi-Rate) coder that was adopted by ETSI and 3GPP as a standard vocoder for next generation IMT-2000 service in which includes combined sender (FEC) and receiver reconstruction technique in the Internet. By use of the media-specific FEC scheme, the possibility to recover lost packets can be much increased due to the addition of repair data to a main data stream, by which the contents of lost packets can be recovered. The AMR codec is based on the code-excited linear predictive (CELP) coding model. So we use a frame erasure concealment for CELP-based coders. The proposed scheme is evaluated with ITU-T G.729 (CS-ACELP) coder and AMR - 12.2 kbit/s through the SNR (Signal to Noise Ratio) and the MOS (Mean Opinion Score) test. The proposed scheme provides 1.1 higher in Mean Opinion Score value and 5.61 dB higher than AMR - 12.2 kbit/s in terms of SNR in 10% packet loss, and maintains the communicab1e quality speech at frame erasure rates lop to 20%.

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What will be the Proper Criteria for Impaired Fasting Glucose for Korean Men? - Based on Medical Screening Data from a General Hospital - (공복혈당장애의 기준 하한치에 관한 코호트연구 - 일개병원 종합건강자료를 중심으로 -)

  • Ryu, Seung-Ho;Kim, Dong-Il;Suh, Byung-Seong;Kim, Woon-Sool;Chang, Yoo-Soo
    • Journal of Preventive Medicine and Public Health
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    • v.38 no.2
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    • pp.203-207
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    • 2005
  • Objectives: Recently, the American Diabetes Association (ADA) redefined the criteria of prediabetes, which has lowered the diagnostic level of fasting plasma glucose (FPG) from 110 to 125 mg/dl, down to levels between 100 to 125mg/dl. The purpose of this study was to determine the predictive cutoff level of FPG as a risk for the development of diabetes mellitus in Korean men. Methods: A retrospective cohort study was conducted on 11,423 (64.5%) out of 17,696 males $\leq$30 years of age, and who met the FPG of $\leq$125 mg/dl and hemoglobin A1c of $\leq$ 6.4% criteria, without a history of diabetes, and who were enrolled at the screening center of a certain university hospital between January and December 1999. The subjects were followed from January 1999 to December 2002 (mean follow-up duration; 2.3(${\pm}0.7$) years). They were classified as normal (FPG <100mg/dl), high glucose (FPG $\geq$100mg/dl and <110mg/dl) and impaired fasting glucose (FPG $\geq$110mg/dl and $\leq$125mg/dl) on the basis of their fasting plasma glucose level measured in 1999. We compared the incidence of diabetes between the 3 groups by performing Cox proportional hazards model and used receiver operating characteristic analyses of the FPG level, in order to estimate the optimal cut-off values as predictors of incident diabetes. Results: At the baseline, most of the study subjects were in age in their 30s to 40s (mean age, 41.8(${\pm}7.1$) year). The incidence of diabetes mellitus in this study was 1.19 per 1,000 person-years (95% CI=0.68-1.79), which was much lower than the results of a community-based study that was 5.01 per 1,000 person-years. The relative risks of incident diabetes in the high glucose and impaired fasting glucose groups, compared with the normal glucose group, were 10.3 (95% CI=2.58-41.2) and 95.2 (95% CI= 29.3-309.1), respectively. After adjustment for age, body mass index, and log triglyceride, a FPG greater than 100mg/dl remained significant predictors of incident diabetes. Using the receiver operating characteristic (ROC) curve, the optimal cutoff level of FPG as a predictor of incident diabetes was 97.5 mg/dl, with a sensitivity and a specificity of 81.0% and 86.0%, respectively. Conclusion: These results suggest that lowering the criteria of impaired fasting glucose is needed in Korean male adults. Future studies on community-based populations, including women, will be required to determine the optimal cutoff level of FPG as a predictor of incident diabetes.

Role of a Risk of Malignancy Index in Clinical Approaches to Adnexal Masses

  • Simsek, Hakki Sencer;Tokmak, Aytekin;Ozgu, Emre;Doganay, Melike;Danisman, Nuri;Erkaya, Salim;Gungor, Tayfun
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.18
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    • pp.7793-7797
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    • 2014
  • Objective: The aim of this study was to evaluate predictive role of risk of malignancy index in discriminating between benign and malignant adnexal masses preoperatively. Methods: This retrospective study was conducted with a total of 569 patients with adnexal masses/ovarian cysts managed surgically at our clinic between January 2006 and January 2012. Obtained data from patient files were age, gravidity, parity, menopause status, ultrasound findings and CA125 levels. For all patients ultrasound scans were performed. For the assessment of risk of malignancy index (RMI) Jacobs' model was used. Histopathologic results of all patients were recorded postoperatively. Malignancy status of the surgically removed adnexal mass was the gold standard. Results: Of the total masses, 245 (43.1%) were malignant, 316 (55.5%) were benign and 8 (1.4%) were borderline. The mean age of benign cases was lower than malign cases ($35.2{\pm}10.9$ versus $50.8{\pm}13.4$, p<0.001). Four hundred and five of them (71.2%) were in premenopausal period. Malignant tumors were more frequent in postmenopausal women (81% versus 29%, p<0.001). All ultrasound parameters of RMI were statistically significantly favorable for malignant masses. In our study ROC curve analysis for RMI provided maximum Youden index at level of 163.85. When we based on cutoff level for RMI as 163.85 sensitivity, specificity, PPV, NPV was calculated 74.7%, 96.2%, 94% and 82.6%, respectively. Conclusions: RMI was found to be a significant marker in preoperative evaluation and management of patients with an adnexal mass, and was useful for referring patients to tertiary care centers. Although utilization of RMI provides increased diagnostic accuracy in preoperative evaluation of patient with an adnexal mass, new diagnostic tools with higher sensitivity and specificity are needed to discriminate ovarian cancer from benign masses.

Application of Residual Statics to Land Seismic Data: traveltime decomposition vs stack-power maximization (육상 탄성파자료에 대한 나머지 정적보정의 효과: 주행시간 분해기법과 겹쌓기제곱 최대화기법)

  • Sa, Jinhyeon;Woo, Juhwan;Rhee, Chulwoo;Kim, Jisoo
    • Geophysics and Geophysical Exploration
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    • v.19 no.1
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    • pp.11-19
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    • 2016
  • Two representative residual static methods of traveltime decomposition and stack-power maximization are discussed in terms of application to land seismic data. For the model data with synthetic shot/receiver statics (time shift) applied and random noises added, continuities of reflection event are much improved by stack-power maximization method, resulting the derived time-shifts approximately equal to the synthetic statics. Optimal parameters (maximum allowable shift, correlation window, iteration number) for residual statics are effectively chosen with diagnostic displays of CSP (common shot point) stack and CRP (common receiver point) stack as well as CMP gather. In addition to removal of long-wavelength time shift by refraction statics, prior to residual statics, processing steps of f-k filter, predictive deconvolution and time variant spectral whitening are employed to attenuate noises and thereby to minimize the error during the correlation process. The reflectors including horizontal layer of reservoir are more clearly shown in the variable-density section through repicking the velocities after residual statics and inverse NMO correction.

An Active Queue Management Method Based on the Input Traffic Rate Prediction for Internet Congestion Avoidance (인터넷 혼잡 예방을 위한 입력율 예측 기반 동적 큐 관리 기법)

  • Park, Jae-Sung;Yoon, Hyun-Goo
    • 전자공학회논문지 IE
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    • v.43 no.3
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    • pp.41-48
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    • 2006
  • In this paper, we propose a new active queue management (AQM) scheme by utilizing the predictability of the Internet traffic. The proposed scheme predicts future traffic input rate by using the auto-regressive (AR) time series model and determines the future congestion level by comparing the predicted input rate with the service rate. If the congestion is expected, the packet drop probability is dynamically adjusted to avoid the anticipated congestion level. Unlike the previous AQM schemes which use the queue length variation as the congestion measure, the proposed scheme uses the variation of the traffic input rate as the congestion measure. By predicting the network congestion level, the proposed scheme can adapt more rapidly to the changing network condition and stabilize the average queue length and its variation even if the traffic input level varies widely. Through ns-2 simulation study in varying network environments, we compare the performance among RED, Adaptive RED (ARED), REM, Predicted AQM (PAQM) and the proposed scheme in terms of average queue length and packet drop rate, and show that the proposed scheme is more adaptive to the varying network conditions and has shorter response time.

Albumin-globulin Ratio for Prediction of Long-term Mortality in Lung Adenocarcinoma Patients

  • Duran, Ayse Ocak;Inanc, Mevlude;Karaca, Halit;Dogan, Imran;Berk, Veli;Bozkurt, Oktay;Ozaslan, Ersin;Ucar, Mahmut;Eroglu, Celalettin;Ozkan, Metin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6449-6453
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    • 2014
  • Background: Prior studies showed a relationship between serum albumin and the albumin to globulin ratio with different types of cancer. We aimed to evaluate the predictive value of the albumin-globulin ratio (AGR) for survival of patients with lung adenocarcinoma. Materials and Methods: This retrospective study included 240 lung adenocarcinoma patients. Biochemical parameters before chemotherapy were collected and survival status was obtained from the hospital registry. The AGR was calculated using the equation AGR=albumin/(total protein-albumin) and ranked from lowest to highest, the total number of patients being divided into three equal tertiles according to the AGR values. Furthermore, AGR was divided into two groups (low and high tertiles) for ROC curve analysis. Cox model analysis was used to evaluate the prognostic value of AGR and AGR tertiles. Results: The mean survival time for each tertile was: for the $1^{st}$ 9.8 months (95%CI:7.765-11.848), $2^{nd}$ 15.4 months (95%CI:12.685-18.186), and $3^{rd}$ 19.9 months (95%CI:16.495-23.455) (p<0.001). Kaplan-Meier curves showed significantly higher survival rates with the third and high tertiles of AGR in comparison with the first and low tertiles, respectively. At multivariate analysis low levels of albumin and AGR, low tertile of AGR and high performance status remained an independent predictors of mortality. Conclusions: Low AGR was a significant predictor of long-term mortality in patients with lung adenocarcinoma. Serum albumin measurement and calculation of AGR are easily accessible and cheap to use for predicting mortality in patients with lung adenocarcinoma.

Design of ASM-based Face Recognition System Using (2D)2 Hybird Preprocessing Algorithm (ASM기반 (2D)2 하이브리드 전처리 알고리즘을 이용한 얼굴인식 시스템 설계)

  • Kim, Hyun-Ki;Jin, Yong-Tak;Oh, Sung-Kwun
    • Journal of the Korean Institute of Intelligent Systems
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    • v.24 no.2
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    • pp.173-178
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    • 2014
  • In this study, we introduce ASM-based face recognition classifier and its design methodology with the aid of 2-dimensional 2-directional hybird preprocessing algorithm. Since the image of face recognition is easily affected by external environments, ASM(active shape model) as image preprocessing algorithm is used to resolve such problem. In particular, ASM is used widely for the purpose of feature extraction for human face. After extracting face image area by using ASM, the dimensionality of the extracted face image data is reduced by using $(2D)^2$hybrid preprocessing algorithm based on LDA and PCA. Face image data through preprocessing algorithm is used as input data for the design of the proposed polynomials based radial basis function neural network. Unlike as the case in existing neural networks, the proposed pattern classifier has the characteristics of a robust neural network and it is also superior from the view point of predictive ability as well as ability to resolve the problem of multi-dimensionality. The essential design parameters (the number of row eigenvectors, column eigenvectors, and clusters, and fuzzification coefficient) of the classifier are optimized by means of ABC(artificial bee colony) algorithm. The performance of the proposed classifier is quantified through yale and AT&T dataset widely used in the face recognition.