• Title/Summary/Keyword: predictor models

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Estimating Grain Weight and Grain Nitrogen Content with Temperature, Solar Radiation and Growth Traits During Grain-Filling Period in Rice (등숙기 온도 및 일사량과 생육형질을 이용한 벼 종실중 및 종실질소함량 추정)

  • Lee, Chung-Kuen;Kim, Jun-Hwan;Son, Ji-Young;Yoon, Young-Hwan;Seo, Jong-Ho;Kwon, Young-Up;Shin, Jin-Chul;Lee, Byun-Woo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.55 no.4
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    • pp.275-283
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    • 2010
  • This experiment was conducted to construct process models to estimate grain weight (GW) and grain nitrogen content (GN) in rice. A model was developed to describe the dynamic pattern of GW and GN during grain-filling period considering their relationships with temperature, solar radiation and growth traits such as LAI, shoot dry-weight, shoot nitrogen content, grain number during grain filling. Firstly, maximum grain weight (GWmax) and maximum grain nitrogen content (GNmax) equation was formulated in relation to Accumulated effective temperature (AET) ${\times}$ Accumulated radiation (AR) using boundary line analysis. Secondly, GW and GN equation were created by relating the difference between GW and GWmax and the difference between GN and GNmax, respectively, with growth traits. Considering the statistics such as coefficient of determination and relative root mean square of error and number of predictor variables, appropriate models for GW and GN were selected. Model for GW includes GWmax determined by AET ${\times}$ AR, shoot dry weight and grain number per unit land area as predictor variables while model for GN includes GNmax determined by AET ${\times}$ AR, shoot N content and grain number per unit land area. These models could explain the variations of GW and GN caused not only by variations of temperature and solar radiation but also by variations of growth traits due to different sowing date, nitrogen fertilization amount and row spacing with relatively high accuracy.

Forecasting Brown Planthopper Infestation in Korea using Statistical Models based on Climatic tele-connections (기후 원격상관 기반 통계모형을 활용한 국내 벼멸구 발생 예측)

  • Kim, Kwang-Hyung;Cho, Jeapil;Lee, Yong-Hwan
    • Korean journal of applied entomology
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    • v.55 no.2
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    • pp.139-148
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    • 2016
  • A seasonal outlook for crop insect pests is most valuable when it provides accurate information for timely management decisions. In this study, we investigated probable tele-connections between climatic phenomena and pest infestations in Korea using a statistical method. A rice insect pest, brown planthopper (BPH), was selected because of its migration characteristics, which fits well with the concept of our statistical modelling - utilizing a long-term, multi-regional influence of selected climatic phenomena to predict a dominant biological event at certain time and place. Variables of the seasonal climate forecast from 10 climate models were used as a predictor, and annual infestation area for BPH as a predictand in the statistical analyses. The Moving Window Regression model showed high correlation between the national infestation trends of BPH in South Korea and selected tempo-spatial climatic variables along with its sequential migration path. Overall, the statistical models developed in this study showed a promising predictability for BPH infestation in Korea, although the dynamical relationships between the infestation and selected climatic phenomena need to be further elucidated.

Crown Fuel Characteristics and Fuel Load Estimation of Pinus densiflora S. et Z. in Bonghwa, Gyeongbuk (경북 봉화 지역 소나무림에 대한 수관연료 특성과 연료량 추정)

  • Jang, Mina;Lee, Byungdoo;Seo, Yeonok;Kim, Sungyong;Lee, Young Jin
    • Journal of Korean Society of Forest Science
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    • v.100 no.3
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    • pp.402-407
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    • 2011
  • The objectives of this study were to analyze the crown vertical structure, crown bulk density, and to develop regression models for predicting crown fuel load using the data from 10 destructively sampled Pinus densiflora trees in Bonghwa, Gyeongbuk. The fuel loads were observed higher in the middle portion of the vertical distribution of crown followed by the lower portion and upper portion of Pinus densiflora, respectively. Approximately 25% crown fuel load was found in the needle while 33% was observed in the branches with <1 cm diameter with a total of 58% available fuel loads. The average crown bulk density was $0.45kg/m^3$, and $0.27kg/m^3$ of this was available in the needles and branches with <1 cm diameters. The resulting models in linear equations were able to account for 84% and 88% of the observed variation, while the allometric equations with diameter at breast height as the single predictor showed better results to account for 90% and 95% of the observed variation in the available crown fuel loads and total crown fuel loads, respectively. The suggested equations in this study could provide quantitative fuel load attributes for crown fire behavior models and fire management of red pine stands in Bonghwa areas.

Determining Nitrogen Topdressing Rate at Panicle Initiation Stage of Rice based on Vegetation Index and SPAD Reading (유수분화기 식생지수와 SPAD값에 의한 벼 질소 수비 시용량 결정)

  • Kim Min-Ho;Fu Jin-Dong;Lee Byun-Woo
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.5
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    • pp.386-395
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    • 2006
  • The core questions for determining nitrogen topdress rate (Npi) at panicle initiation stage (PIS) are 'how much nitrogen accumulation during the reproductive stage (PNup) is required for the target rice yield or protein content depending on the growth and nitrogen nutrition status at PIS?' and 'how can we diagnose the growth and nitrogen nutrition status easily at real time basis?'. To address these questions, two years experiments from 2001 to 2002 were done under various rates of basal, tillering, and panicle nitrogen fertilizer by employing a rice cultivar, Hwaseongbyeo. The response of grain yield and milled-rice protein content was quantified in relation to RVIgreen (green ratio vegetation index) and SPAD reading measured around PIS as indirect estimators for growth and nitrogen nutrition status, the regression models were formulated to predict PNup based on the growth and nitrogen nutrition status and Npi at PIS. Grain yield showed quadratic response to PNup, RVIgreen around PIS, and SPAD reading around PIS. The regression models to predict grain yield had a high determination coefficient of above 0.95. PNup for the maximum grain yield was estimated to be 9 to 13.5 kgN/10a within the range of RVIgreen around PIS of this experiment. decreasing with increasing RVIgreen and also to be 10 to 11 kgN/10a regardless of SPAD readings around PIS. At these PNup's the protein content of milled rice was estimated to rise above 9% that might degrade eating quality seriously Milled-rice protein content showed curve-linear increase with the increase of PNup, RVIgreen around PIS, and SPAD reading around PIS. The regression models to predict protein content had a high determination coefficient of above 0.91. PNup to control the milled-rice protein content below 7% was estimated as 6 to 8 kgN/10a within the range of RVIgreen and SPAD reading of this experiment, showing much lower values than those for the maximum grain yield. The recovery of the Npi applied at PIS ranged from 53 to 83%, increasing with the increased growth amount while decreasing with the increasing Npi. The natural nitrogen supply from PIS to harvest ranged from 2.5 to 4 kg/10a, showing quadratic relationship with the shoot dry weight or shoot nitrogen content at PIS. The regression models to estimate PNup was formulated using Npi and anyone of RVIgreen, shoot dry weight, and shoot nitrogen content at PIS as predictor variables. These models showed good fitness with determination coefficients of 0.86 to 0.95 The prescription method based on the above models predicting grain yield, protein content and PNup and its constraints were discussed.

Awareness of General Public Towards Cancer Prostate and Screening Practice in Arabic Communities: a Comparative Multi-Center Study

  • Arafa, Mostafa A.;Rabah, Danny M.;Wahdan, Iman H.
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.9
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    • pp.4321-4326
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    • 2012
  • The current study aimed at exploring the knowledge and beliefs of men aged forty years and over towards prostate cancer screening and early detection in three Arab countries. The field work was conducted in three countries; Saudi Arabia, Egypt and Jordan, during the period February through December 2011. Our target population were men aged 40 years and over. It was a population-based cross sectional study comprising 400 subjects at each site. In addition to socio-demographic data, history of the present and past medical illness, practice history of prostatic cancer examination, family history of cancer prostate; participants were inquired about their knowledge and attitude towards prostate cancer and screening behavior using two different likert scales. The percentage of participants who practiced regular prostate check up ranged from 8-30%. They had poor knowledge and fair attitude towards prostate cancer screening behavior, where the mean total knowledge score was $10.25{\pm}2.5$, $10.76{\pm}3.39$ and $11.24{\pm}3.39$ whereas the mean total attitude score was $18.3{\pm}4.08$, $20.68{\pm}6.4$ and $17.96{\pm}5.3$ for Saudi Arabia, Egypt and Jordan respectively. The respondents identified the physicians as the main sources of this information (62.4%), though they were not the main motives for regular checkup. Knowledge was the only significant predictor for participants' attitude in the multiple regression models. Participants' attitudes depends mainly on level of knowledge and quantity of information provided to the patients and their families. Such attitudes should rely on a solid background of proper information and motivation from physicians to enhance and empower behaviors towards prostate cancer screening practices.

Prognostic Value of Lymph Node Ratios in Node Positive Rectal Cancer Treated with Preoperative Chemoradiation

  • Nadoshan, Jamal Jafari;Omranipour, Ramesh;Beiki, Omid;Zendedel, Kazem;Alibakhshi, Abbas;Mahmoodzadeh, Habibollah
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.6
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    • pp.3769-3772
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    • 2013
  • Background: To investigate the impact of the lymph node ratio (LNR) on the prognosis of patients with locally advanced rectal cancer undergoing pre-operative chemoradiation. Methods: Clinicopathologic and follow up data of 128 patients with stage III rectal cancer who underwent curative resection from 1996 to 2007 were reviewed. The patients were divided into two groups according to the lymph node ratio: LNR ${\leq}$ 0.2 (n=28), and >0.2 (n=100). Kaplan-Meier and the Cox proportional hazard regression models were used to evaluate the prognostic effects according to LNR. Results: Median numbers of lymph nodes examined and lymph nodes involved by tumour were 10.3 (range 2-28) and 5.8 (range 1-25), respectively, and the median LNR was 0.5 (range, 0-1.6). The 5-year survival rate significantly differed by LNR (${\leq}$ 0.2, 69%; >0.2, 19%; Log-rank p value < 0.001). LNR was also a significant prognostic factor of survival adjusted for age, sex, post-operative chemotherapy, total number of examined lymph nodes, metastasis and local recurrence (${\leq}$ 0.2, HR=1; >0.2, HR=4.8, 95%CI=2.1-11.1) and a significant predictor of local recurrence and distant metastasis during follow-up independently of total number of examined lymph node. Conclusions: Total number of examined lymph nodes and LNR were significant prognostic factors for survival in patients with stage III rectal cancer undergoing pre-operative chemoradiotherapy.

Prediction Model for the Risk of Scapular Winging in Young Women Based on the Decision Tree

  • Gwak, Gyeong-tae;Ahn, Sun-hee;Kim, Jun-hee;Weon, Young-soo;Kwon, Oh-yun
    • Physical Therapy Korea
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    • v.27 no.2
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    • pp.140-148
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    • 2020
  • Background: Scapular winging (SW) could be caused by tightness or weakness of the periscapular muscles. Although data mining techniques are useful in classifying or predicting risk of musculoskeletal disorder, predictive models for risk of musculoskeletal disorder using the results of clinical test or quantitative data are scarce. Objects: This study aimed to (1) investigate the difference between young women with and without SW, (2) establish a predictive model for presence of SW, and (3) determine the cutoff value of each variable for predicting the risk of SW using the decision tree method. Methods: Fifty young female subjects participated in this study. To classify the presence of SW as the outcome variable, scapular protractor strength, elbow flexor strength, shoulder internal rotation, and whether the scapula is in the dominant or nondominant side were determined. Results: The classification tree selected scapular protractor strength, shoulder internal rotation range of motion, and whether the scapula is in the dominant or nondominant side as predictor variables. The classification tree model correctly classified 78.79% (p = 0.02) of the training data set. The accuracy obtained by the classification tree on the test data set was 82.35% (p = 0.04). Conclusion: The classification tree showed acceptable accuracy (82.35%) and high specificity (95.65%) but low sensitivity (54.55%). Based on the predictive model in this study, we suggested that 20% of body weight in scapular protractor strength is a meaningful cutoff value for presence of SW.

Image-adaptive Lossless Image Compression (영상 적응형 무손실 영상 압축)

  • 원종우;오현종;장의선
    • Journal of Broadcast Engineering
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    • v.9 no.3
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    • pp.246-256
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    • 2004
  • In this paper, we proposed a new lossless image compression algorithm. Lossless image compression has been used in the field that requires the accuracy and precision. Thus, application areas using medical unaging, prepress unaging, image archival systems, precious artworks to be preserved, and remotely sensed images require lossless compression. The compression ratio from lossless image compression has not been satisfactory, thus far. So, new method of lossless image compression has been investigated to get better compression efficiency. We have compared the compression results with the most typical compression methods such as CALIC and JPEG-LS. CALIC has shown the best compression-ratio among the existing lossless coding methods at the cost of the extensive complexity by three pass algorithm. On the other hand, JPEG-LS's compression-ratio is not higher than CALIC, but was adopted as an international standard of ISO because of the low complexity and fast coding process. In the proposed method, we adopted an adaptive predictor that can exploit the characteristics of individual images, and an adaptive arithmetic coding with multiple probability models. As a result, the proposed algorithm showed 5% improvement in compression efficiency in comparison with JPEG-LS and showed comparable compression ratio with CALIC.

A Structural Model for Premenstrual Coping in University Students: Based on Biopsychosocial Model (생물심리사회모델에 근거한 여대생의 월경전증후군 대처 예측모형)

  • Chae, Myung-Ock;Jeon, Hae Ok;Kim, Ahrin
    • Journal of Korean Academy of Nursing
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    • v.47 no.2
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    • pp.257-266
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    • 2017
  • Purpose: The aims of this study were to construct a hypothetical structural model which explains premenstrual coping in university students and to test the fitness with collected data. Methods: Participants were 206 unmarried women university students from 3 universities in A and B cities. Data were collected from March 29 until April 30, 2016 using self-report structured questionnaires and were analyzed using IBM SPSS 23.0 and AMOS 18.0. Results: Physiological factor was identified as a significant predictor of premenstrual syndrome (t=6.45, p<.001). This model explained 22.1% of the variance in premenstrual syndrome. Psychological factors (t=-2.49, p=.013) and premenstrual syndrome (t=8.17, p<.001) were identified as significant predictors of premenstrual coping. Also this model explained 30.9% of the variance in premenstrual coping in university students. A physiological factors directly influenced premenstrual syndrome (${\beta}=.41$, p=.012). Premenstrual syndrome (${\beta}=.55$, p=.005) and physiological factor (${\beta}=.23$, p=.015) had significant total effects on premenstrual coping. Physiological factor did not have a direct influence on premenstrual coping, but indirectly affected it (${\beta}=.22$, p=.007). Psychological factors did not have an indirect or total effect on premenstrual coping, but directly affected it (${\beta}=-.17$, p=.036). Conclusion: These findings suggest that strategies to control physiological factors such as menstrual pain should be helpful to improve premenstrual syndrome symptoms. When developing a program to improve premenstrual coping ability and quality of menstrual related health, it is important to consider psychological factors including perceived stress and menstrual attitude and premenstrual syndrome.

The Association between Bone Density at Os Calcis and Body Composition in Healthy Children Aged 9-12 Years (9-12세 정상 아동에서 종골 골밀도와 체성분의 연관성)

  • Shin, Eun-Kyung;Kim, Ki-Suk;Kim, Hee-Young;Lee, In-Sook;Joung, Hyo-Jee;Cho, Sung-Il
    • Journal of Preventive Medicine and Public Health
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    • v.37 no.1
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    • pp.72-79
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    • 2004
  • Objectives : This cross-sectional study aimed to quantify the relationship between the bone mineral density at the os calcis and the body mass composition in healthy children. Methods : The areal bone mineral density was measured at the os calcis with peripheral dual energy X-ray absorptiometry. The fat free mass, fat mass and percentage fat mass were measured using bioelectric impedance, in 237 Korean children, aged 9 to 12 years. The sexual maturity was determined by self assessment, using standardized series of the 5 Tanner stage drawings, accompanied by explanatory text. Results : From multiple linear regression models, adjusted for age, sexual maturity and height, the fat free mass was found to be the best predictor of the calcaneal bone mineral density in both sexes. About 15 and 20% variabilities were found in the calcaneal bone mineral densities of the boys and girls, respectively, which can be explained by the fat free mass. After weight adjustment, the percentage fat mass was negatively associated with the calcaneal bone mineral density in both sexes. Conclusions : The findings of this study suggest that the fat free mass, among the body compositions, is the major determinant of bone mineral density at the os calcis in Korean children aged 9 to 12 years. Obesity, defined as the percentage fat mass, is assumed to have a negative effect on the calcaneal bone density in children of the same weight.