• Title/Summary/Keyword: Linear-quadratic model

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Determination of the Optimal Mixture Ratio for Extrudates of Job's-tear and Wheat Flour by Mixture Design Analysis (혼합실험계획법에 의한 율무와 밀가루의 압출성형 최적 배합 조건 설정)

  • Cho, Seok-Cheol;Kang, Byung-Sun
    • Korean Journal of Food Science and Technology
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    • v.45 no.4
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    • pp.473-477
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    • 2013
  • The aim of this study was to identify the optimal ingredient-mixing ratio of Job's-tear and wheat flour subjected to extrusion. A modified distance-based mixture design analysis was chosen for the experimental design. The results showed that the bending failure force, the a-value, and the water absorbtion index (WAI) value had no correlation with the mixture ratio of Job's-tear and wheat flour. However, the diameter of the extrudates, the L- and b-values, and the water solubility index (WSI) value were all found to be correlated to the mixture ratio. While the first three values were determined using a linear model, the WSI value was determined using a quadratic model. The diameter and color had an inverse correlation to the mixture ratio: the higher the ratio of Job's-tear to wheat flour, the lower the diameter and darker the color. The L- and b-values were found to change in accordance with the mixture ratio of Job's-tear to wheat flour. The lowest WSI value was obtained at a 40:60 ratio of Job's-tear to wheat.

The Effects of Headquarters' Levels of Control and Subsidiaries' Local Experiences on Competency in Foreign Subsidiaries: A Quadratic Model Investigation of Korean Multinational Corporations

  • Lee, Jae-Eun;Kang, Joo-Yeon;Park, Jung-Min
    • Journal of Korea Trade
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    • v.24 no.1
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    • pp.82-98
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    • 2020
  • Purpose - This study aims to overcome the limitations of existing studies, which linearly determine the precedence factors of competency in overseas subsidiaries. The research objectives are as follows. First, what kind of nonlinear effects does the level of control held by Korean headquarters over foreign subsidiaries have in terms of competency in the subsidiaries? Second, what kind of nonlinear effects do the local experiences of overseas subsidiaries have on their competency? Design/methodology - With data on Korean multinational corporations (MNCs), this paper analyzes the effects of control levels of headquarters (HQs) and host-country experiences of foreign subsidiaries regarding competency in overseas subsidiaries. In particular, this study focuses on nonlinear models, differentiating it from previous studies. In order to examine research hypotheses, this study conducted a survey of overseas subsidiaries of Korean corporations. Surveys were conducted through various methods including e-mail, online questionnaires, fax, and telephone calls. Copies of the questionnaire were distributed to a total of 2,246 overseas subsidiaries, and 409 completed responses were collected. Excluding 15 copies that were insufficiently answered, responses from a total of 394 copies were used for analysis. Findings - This study presents the following results. First, there is a U-shaped relationship between levels of HQ control and competency in foreign subsidiaries. This means that higher levels of HQ control negatively impact the competency levels of subsidiaries because strict control undermines autonomy in subsidiaries. However, if the level of HQ control exceeds a certain point, then the transfer of knowledge between HQs and subsidiaries is facilitated. Knowledge transferred from HQs can be used as prior knowledge by foreign subsidiaries to the benefit of all parties. Accordingly, knowledge transfer negates the negative effects of excessive HQ control and positively affects competency in subsidiaries. Second, there is an inverted U-shaped relationship between the local (host-country) experiences of subsidiaries and competency in foreign subsidiaries. This means that foreign subsidiaries can overcome the liabilities of foreignness and contribute to capability building by accumulating unique knowledge about their host countries. However, if local experiences accumulate excessively beyond a certain point, then the host country-specific experiences of foreign subsidiaries will offset the benefits discussed above. Excessive local experiences not only increase organizational inertia, but also create a problem of goal incongruence due to information asymmetry between HQs and subsidiaries. Therefore, excessive local experiences have negative effects on competency in foreign subsidiaries. Originality/value - This study suggests the following implications. First, unlike existing studies based mainly on linear models, this study presents important theoretical implications in its focus on nonlinear models and its analysis of the effects of HQ control and local experiences on competency in foreign subsidiaries from perspectives of organizational learning theory and agency theory. Second, in terms of practical implications, the results of this study suggest that optimally raising levels of HQ control and managing the local experiences of subsidiaries without increasing organizational inertia is important for enhancing competency in foreign subsidiaries.

Effects of dietary flavonoids on performance, blood constituents, carcass composition and small intestinal morphology of broilers: a meta-analysis

  • Prihambodo, Tri Rachmanto;Sholikin, Muhammad Miftakhus;Qomariyah, Novia;Jayanegara, Anuraga;Batubara, Irmanida;Utomo, Desianto Budi;Nahrowi, Nahrowi
    • Animal Bioscience
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    • v.34 no.3_spc
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    • pp.434-442
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    • 2021
  • Objective: This study aims to evaluate the influence of dietary flavonoids on the growth performance, blood and intestinal profiles, and carcass characteristics of broilers by employing a meta-analysis method. Methods: A database was built from published studies which have reported on the addition of various levels of flavonoids from herbs into broiler diets and then monitored growth performance, blood constituents, carcass proportion and small intestinal morphology. A total of 42 articles were integrated into the database. Several forms of flavonoids in herbs were applied in the form of unextracted and crude extracts. The database compiled was statistically analyzed using mixed model methodology. Different studies were considered as random effects, and the doses of flavonoids were treated as fixed effects. The model statistics used were the p-values and the Akaike information criterion. The significance of an effect was stated when its p-value was <0.05. Results: Dietary flavonoids increased (quadratic pattern; p<0.05) the average daily gain of broilers in the finisher phase. There was a reduction (p<0.01) in the feed conversion ratio of the broilers both in the starter (linear pattern) and finisher phases (quadratic pattern). The mortality rate tended to decrease linearly (p<0.1) with the addition of flavonoids, while the carcass parameter was generally not influenced. A reduction (p<0.001) in cholesterol and malondialdehyde concentrations (both linearly) was observed, while super oxide dismutase activity increased linearly (p<0.001). Increasing the dose of flavonoids increased (p<0.01) the villus height (VH) and villus height and crypt depth (VH:CD) ratio (p<0.05) in the duodenum. Similarly, the VH:CD ratio was elevated (p<0.001) in the jejunum following flavonoid supplementation. Conclusion: Increasing levels of flavonoids in broilers diet leads to an improvement in growth performance, blood constituents, carcass composition and small intestinal morphology.

Dual Codec Based Joint Bit Rate Control Scheme for Terrestrial Stereoscopic 3DTV Broadcast (지상파 스테레오스코픽 3DTV 방송을 위한 이종 부호화기 기반 합동 비트율 제어 연구)

  • Chang, Yong-Jun;Kim, Mun-Churl
    • Journal of Broadcast Engineering
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    • v.16 no.2
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    • pp.216-225
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    • 2011
  • Following the proliferation of three-dimensional video contents and displays, many terrestrial broadcasting companies have been preparing for stereoscopic 3DTV service. In terrestrial stereoscopic broadcast, it is a difficult task to code and transmit two video sequences while sustaining as high quality as 2DTV broadcast due to the limited bandwidth defined by the existing digital TV standards such as ATSC. Thus, a terrestrial 3DTV broadcasting with a heterogeneous video codec system, where the left image and right images are based on MPEG-2 and H.264/AVC, respectively, is considered in order to achieve both high quality broadcasting service and compatibility for the existing 2DTV viewers. Without significant change in the current terrestrial broadcasting systems, we propose a joint rate control scheme for stereoscopic 3DTV service based on the heterogeneous dual codec systems. The proposed joint rate control scheme applies to the MPEG-2 encoder a quadratic rate-quantization model which is adopted in the H.264/AVC. Then the controller is designed for the sum of the left and right bitstreams to meet the bandwidth requirement of broadcasting standards while the sum of image distortions is minimized by adjusting quantization parameter obtained from the proposed optimization scheme. Besides, we consider a condition on maintaining quality difference between the left and right images around a desired level in the optimization in order to mitigate negative effects on human visual system. Experimental results demonstrate that the proposed bit rate control scheme outperforms the rate control method where each video coding standard uses its own bit rate control algorithm independently in terms of the increase in PSNR by 2.02%, the decrease in the average absolute quality difference by 77.6% and the reduction in the variance of the quality difference by 74.38%.

Optimization of Muffins Containing Dried Leek Powder Using Response Surface Methodology (부추 분말 첨가 머핀의 제조 조건 최적화)

  • Ryu, Seung-Yeon;Jung, Hee-Sun;Park, Sang-Hyun;Shin, Ji-Hun;Jung, Hyeon-A;Joo, Na-Mi
    • Journal of the Korean Dietetic Association
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    • v.14 no.2
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    • pp.105-113
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    • 2008
  • The purpose of this study was to develop a muffin containing dried leek powder. The complete analysis was conducted using the Design Expert 7 program (Stat - Easy Co., Minneapolis, MN, USA). The leek muffins were produced with varying amounts of leek powder (A), sugar (B), and butter (C). According to response surface methodology (RSM), there were 16 experimental points, including two replicates. The leek muffin formulation was optimized using rheology and sensory analyses. For the results, a quadratic model was applied in determining lightness, volume, hardness, and sensory characteristics, including flavor, texture, and overall quality; redness and height were represented by a linear model. Lightness decreased and redness increased with increasing amounts of leek powder (p<0.001). In addition, hardness displayed significant differences (p<0.001) with increasing amounts of leek powder. The sensory evaluation results showed significant differences for color, flavor, texture, and overall quality (p<0.05). Based on the numerical and graphical methods, the optimal formulation was determined as 8.30 g of leek power, 88.37 g of sugar, and 81.70 g of butter.

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Radiobiological mechanisms of stereotactic body radiation therapy and stereotactic radiation surgery

  • Kim, Mi-Sook;Kim, Wonwoo;Park, In Hwan;Kim, Hee Jong;Lee, Eunjin;Jung, Jae-Hoon;Cho, Lawrence Chinsoo;Song, Chang W.
    • Radiation Oncology Journal
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    • v.33 no.4
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    • pp.265-275
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    • 2015
  • Despite the increasing use of stereotactic body radiation therapy (SBRT) and stereotactic radiation surgery (SRS) in recent years, the biological base of these high-dose hypo-fractionated radiotherapy modalities has been elusive. Given that most human tumors contain radioresistant hypoxic tumor cells, the radiobiological principles for the conventional multiple-fractionated radiotherapy cannot account for the high efficacy of SBRT and SRS. Recent emerging evidence strongly indicates that SBRT and SRS not only directly kill tumor cells, but also destroy the tumor vascular beds, thereby deteriorating intratumor microenvironment leading to indirect tumor cell death. Furthermore, indications are that the massive release of tumor antigens from the tumor cells directly and indirectly killed by SBRT and SRS stimulate anti-tumor immunity, thereby suppressing recurrence and metastatic tumor growth. The reoxygenation, repair, repopulation, and redistribution, which are important components in the response of tumors to conventional fractionated radiotherapy, play relatively little role in SBRT and SRS. The linear-quadratic model, which accounts for only direct cell death has been suggested to overestimate the cell death by high dose per fraction irradiation. However, the model may in some clinical cases incidentally do not overestimate total cell death because high-dose irradiation causes additional cell death through indirect mechanisms. For the improvement of the efficacy of SBRT and SRS, further investigation is warranted to gain detailed insights into the mechanisms underlying the SBRT and SRS.

Optimization of Muffin Preparation by Addition of Dried Burdock (Arctium lappa L) Powder and Oligosaccharide by Response Surface Methodology (반응표면분석법을 이용한 우엉가루와 올리고당 첨가 머핀의 제조 조건 최적화)

  • Kim, Mi-Kyung;Kim, Weon-Mo;Lee, Hey-Joeng;Choi, Eun-Young
    • Korean journal of food and cookery science
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    • v.26 no.5
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    • pp.575-585
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    • 2010
  • This study was performed to determine the optimal composition of a muffin administered dried burdock powder and oligosaccharide. The experiment was designed base on CCD (Central Composite Design), and evaluation was carried out by means of RSM (Response Surface Methodology), which included 10 experimental points with 3 replicates for the two independent variables burdock powder and oligosaccharide. The experimental muffin was made according to a traditional recipe, except that the flour was partially replaced with dried burdock powder (5%, 15%, 25%) and the sugar was partially replaced with oligosaccharide (25%, 50%, 75%). The compositional and functional properties of the prepared products were measured, and these values were applied to the mathematical models. Using the F-test, volume, height, pH, yellowness, chewiness, resilience, springiness, cohesiveness, taste, and overall quality were expressed as a linear model, whereas lightness, redness, adhesiveness, color, flavor, and overall quality were expressed as a quadratic model. The polynomial models developed by RSM for sensory evaluation, color, flavor, texture, taste, and overall quality were highly effective in describing the relationships between the factors (p<0.01). The estimated response surfaces confirmed that the amount of burdock powder had significant effects on color, taste, texture, flavor, and overall quality (p<0.01), whereas and the amount of oligosaccharide had significant effects on color and texture (p<0.01). Increased amount of burdock powder led to reductions of the sensory scores for color, taste, texture, flavor, and overall quality at all oligosaccharide levels. The optimal mixing percentage of burdock powder and oligosaccharide muffin were determined to be 5.00% and 46.25%, respectively.

Statistical Modelling and Forecasting of Cervix Cancer Cases in Radiation Oncology Treatment: A Hospital Based Study from Western Nepal

  • Sathian, Brijesh;Fazil, Abul;Sreedharan, Jayadevan;Pant, Sadip;Kakria, Anjali;Sharan, Krishna;Rajesh, E.;Vishrutha, K.V.;Shetty, Soumya B.;Shahnavaz, Shameema;Rao, Jyothi H.;Marakala, Vijaya
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.2097-2100
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    • 2013
  • Background: To estimate the numbers and trends in cervix cancer cases visiting the Radiotherapy Department at Manipal Teaching Hospital, Pokhara, Nepal, statistical modelling from retrospective data was applied. Materials and Methods: A retrospective study was carried out on data for a total of 159 patients treated for cervix cancer at Manipal Teaching Hospital, Pokhara, Nepal, between $28^{th}$ September 2000 and $31^{st}$ December 2008. Theoretical statistics were used for statistical modelling and forecasting. Results: Using curve fitting method, Linear, Logarithmic, Inverse, Quadratic, Cubic, Compound, Power and Exponential growth models were validated. Including the constant term, none of the models fit the data well. Excluding the constant term, the cubic model demonstrated the best fit, with $R^2$=0.871 (p=0.004). In 2008, the observed and estimated numbers of cases were same (12). According to our model, 273 patients with cervical cancer are expected to visit the hospital in 2015. Conclusions: Our data predict a significant increase in cervical cancer cases in this region in the near future. This observation suggests the need for more focus and resource allocation on cervical cancer screening and treatment.

Optimization of Ingredient Mixing Ratio for Preparation of Steamed Cake with Mugwort (Pseudosasa japonica Makino) Powder (혼합물 실험계획법에 의한 쑥 첨가 찜 케이크의 최적화)

  • Oh, Suk-Tae;Park, Jung-Eun
    • Korean journal of food and cookery science
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    • v.28 no.1
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    • pp.67-76
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    • 2012
  • This study examined the optimal ingredient mixing ratio for the preparation of steamed cake containing mugwort (Artemisia princeps var. orientalis) powder. After preliminary studies, the following ingredient ranges were determined; 110~129% sugar, 3~8% mugwort powder, 10~25% oil. Among the different mixture designs, the D-optimal design was chosen for analysis. The results of F-test, specific gravity, viscosity, volume and color values (L, a, b), hardness decided a linear model, while the sensory characteristics (color, taste, texture and overall acceptance) decided a quadratic model. The fitness analysis results showed that in all characteristic, the probabilities were significant within 0.05%; thus, the models were accepted as appropriate. The response surface and trace plot results showed that increasing amounts of mugwort powder decreased the brightness, and increased redness and yellowness. As the level of added oil increased, the softness of the cake increased. Cake samples received low sensory evaluation scores when sugar, mugwort powder, and oil were added above their optimal levels. The optimum formulations by the numerical and graphical methods, were similar, and with the numerical method presented as: sugar, mugwort powder, and oil at 120.7%, 5.1%, and 16.2%, respectively(flour weight basis). The above results demonstrate the feasibility of adding mugwort powder to sponge cake, and therefore, the commercialization of mugwort powder cake marketed as a functional food is deemed possible.

Optimization of Ingredient Mixing Ratio for Preparation of Sponge Cake with Bamboo (Pseudosasa japonica Makino) Leaves Powder (대나무잎 가루를 첨가한 스펀지 케이크 재료 혼합비율의 최적화)

  • Park, Jung-Eun;Jeong, Heung-Do;Jang, Myung-Sook
    • Korean journal of food and cookery science
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    • v.25 no.3
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    • pp.317-329
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    • 2009
  • In the study, we determined the optimal ingredient mixing ratio for the preparation of sponge cake containing bamboo (Pseudosasa japonica Makino) leaves. This experiment was designed in according with the D-optimal design of mixture design, which involved 14 experimental points including 4 replicates for three independent variables (sugar 110${\sim}$129%, bamboo leaves 3${\sim}$8%, oil 10${\sim}$25%). The results the F-test, specific gravity, volume and color values (L, a, b) decided a linear model, while the viscosity, hardness and sensory characteristics (color, smell, taste, texture and overall acceptance) decided a quadratic model. The results of our fitness analysis demonstrated that in all characteristic, the probabilities were significant within 0.05%; thus, the models were accepted as appropriate. The response surface and trace plot results demonstrated that increasing amounts of added bamboo leaves induced a reduction in brightness, and increasing redness and yellowness. In addition, increasing amounts of bamboo leaves caused increases in hardness, and thus the softness of the cake decreased. And as the level of added oil increased, softness increased. Cake samples received low sensory evaluation scores when sugar, bamboo leaves, and oil were added above their optimal levels. In the numeric optimization, the optimal ingredient amounts were 121.36% sugar, 4.96% bamboo leaves, and 15.69% oil. The above results demonstrate the feasibility of adding bamboo leaves to sponge cake, and therefore, a bamboo leaves as a functional food.