• Title/Summary/Keyword: Parameter study

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An Analysis on the Bleeding Effect of SCW Ground Heat Exchanger using Thermal Response Test Data (열응답시험 데이터를 이용한 SCW형 지중열교환기 블리딩 효과 분석)

  • Chang, Keun-Sun;Kim, Min-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.512-520
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    • 2020
  • Recently, the applications of the standing column well (SCW) ground heat exchanger (GHX) have increased significantly in Korea as a heat transfer mechanism of ground source heat pump systems (GSHP) because of its high heat capacity and efficiency. Among the various design and operating parameters, bleeding was found to be the most important parameter for improving the thermal performance, such as ground thermal conductivity and borehole thermal resistance. In this study, a bleeding analysis model was developed using the thermal response test data, and the effects of bleeding rates and bleeding locations on the thermal performance of anSCW were investigated. The results show that, when the ground water flows into the top of anSCW, the time variation of circulating water temperature decreased with increasing bleeding rate, and the ground thermal conductivity increases by as much as 179% with a 30% bleeding rate. When the ground water flows into the bottom of the SCW, the circulating water temperatures become almost constant after the increase in the beginning time because the circulating water exchanges heat with the ground structure before mixing with the ground water at the bottom.

The Relationship between Explicit/Implicit Dependency and Depression (외현적/암묵적 의존성과 우울과의 관계)

  • Park, Sunhee;Oh, Kyung Ja
    • Korean Journal of Cognitive Science
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    • v.27 no.4
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    • pp.599-618
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    • 2016
  • The relationship between dependent personality traits and depression has been widely studied in the field of psychology. However, the existing evidence is mixed and often contradictory, obscuring the precise nature of this relationship. Given that the most common method of measuring the construct of dependency has been to administer self-report instruments, it is possible that implicit dependency, another parameter of dependency that is distinct from explicit dependency measured via self-report, is confounding these results. The current study aimed to clarify the relationship between dependency and depression by comparing the effect of implicit and explicit dependency. Implicit dependency was measured via the Single Category-Implicit Association Test (SC-IAT), a test of implicit personality that has shown to have good validity and reliability in previous studies. In addition, we examined the effect of gender on this relationship, given the potential role of gender stereotype that may make male participants show lower levels of dependency when measured through self-report (vs. SC-IAT). Results showed that implicit and explicit dependency indeed had separate and distinct relationships, and the relationships depends on participants' gender. Among female participants, increased explicit dependency predicted depression only when implicit dependency was also elevated. In contrast, explicit dependency predicted depression regardless of the level of implicit dependency in male participants. These findings suggest that implicit and explicit dependency may be separate parameters capturing different aspects of dependent personality traits, further supporting the need to consider the implicit aspect of personality in personality assessment research. Implications and limitations of the current findings and directions for future research are discussed.

Development of a self-leveling system for the bucket of an agricultural front-end loader using an electro hydraulic proportional valve and a tilt sensor (전자유압 비례밸브와 경사센서를 이용한 농용 프론트 로더 버켓 능동수평유지 시스템 개발)

  • Lee, Chang Joo;Ha, Jong Woo;Choi, Deok Su;Kim, Hak Jin
    • Journal of Drive and Control
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    • v.12 no.4
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    • pp.60-70
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    • 2015
  • A front-end loader (FEL) mounted on an agricultural tractor is one of the most commonly used implements for farm work. However, when the tractor carries material using the bucket attached to the FEL on a sloping ground, the materials can spill or roll back over the operator due to the tilted body, thereby requiring the bucket surface to remain level at a constant value regardless of varying slopes. In this study, an active system for controlling the angle of the FEL bucket on a tractor based on the real-time measurement of ground slopes was developed to enable the bucket to constantly remain level. A FEL simulator operated based on an electro hydraulic proportional valve (EHPV) was constructed in the laboratory to develop a proportional-integral-derivative (PID) controller forming a virtual electronic control unit (ECU) on the computer, which could automatically adjust the bucket angles depending on varying input angles while sending SAE-J1939 associated messages via CAN BUS to the EHPV. The different parameter values for the PID controller due to the gravity effect of the bucket were determined using a manual PID tuning method while assuming that the tractor travels on either an ascending slope or a descending slope. The developed PID control-based self-leveling system showed a mean of steady-state errors of within $1^{\circ}$ and a mean of delayed times of ~ 0.8s when the step input of $+20^{\circ}$ was given, implying that the developed system and control algorithm would be effective in maintaining the bucket angle at a certain value. Future studies include the improvement of the control algorithm to reduce such a time delay as well as the application of the developed algorithm to the FEL mounted on a tractor tested at a testing ground.

Estimation of Genetic Parameters for Calving Ease by Heifers and Cows Using Multi-trait Threshold Animal Models with Bayesian Approach

  • Lee, D.H.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.8
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    • pp.1085-1090
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    • 2002
  • Genetic parameters for birth weights (BWT), calving ease scores observed from calves born by heifers (CEH), and calving ease scores observed from calves born by cows (CEC) were estimated using Bayesian methodology with Gibbs sampling in different threshold animal models. Data consisted of 77,458 records for calving ease scores and birth weights in Gelbvieh cattle. Gibbs samplers were used to obtain the parameters of interest for the categorical traits in two univariate threshold animal models, a bivariate threshold animal model, and a three-trait linear-threshold animal model. Samples of heritabilities and genetic correlations were calculated from the posterior means of dispersion parameters. In a univariate threshold animal model with CEH (model 1), the posterior means of heritabilities for calving ease was 0.35 for direct genetic effects and 0.18 for maternal genetic effects. In the other univariate threshold model with CEC (model 2), the posterior means of heritabilities of CEC was 0.28 for direct genetic effects and 0.18 for maternal genetic effects. In a bivariate threshold model with CEH and CEC (model 3), heritability estimates were similar to those in unvariate threshold models. In this model, genetic correlation between heifer calving ease and cow calving ease was 0.89 and 0.87 for direct genetic effect and maternal genetic effects, respectively. In a three-trait animal model, which contained two categorical traits (CEH and CEC) and one continuous trait (BWT) (model 4), heritability estimates of CEH and CEC for direct (maternal) genetic effects were 0.40 (0.23) and 0.23 (0.13), respectively. In this model, genetic correlation estimates between CEH and CEC were 0.89 and 0.66 for direct genetic effects and maternal effects, respectively. These estimates were greater than estimates between BWT and CEH (0.82 and 0.34) or BWT and CEC (0.85 and 0.26). This result indicates that CEH and CEC should be high correlated rather than estimates between calving ease and birth weight. Genetic correlation estimates between direct genetic effects and maternal effects were -0.29, -0.31 and 0.15 for BWT, CEH and CEC, respectively. Correlation for permanent environmental effects between BWT and CEC was -0.83 in model 4. This study can provide genetic evaluation for calving ease with other continuous traits jointly with assuming that calving ease from first calving was a same trait to calving ease from later parities calving. Further researches for reliability of dispersion parameters would be needed even if the more correlated traits would be concerned in the model, the higher reliability could be obtained, especially on threshold model with property that categorical traits have little information.

Red Color Light at Different Intensities Affects the Performance, Behavioral Activities and Welfare of Broilers

  • Senaratna, D.;Samarakone, T.S.;Gunawardena, W.W.D.A.
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.7
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    • pp.1052-1059
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    • 2016
  • Red light (RL) marked higher weight gain (WG) and preference of broilers compared to other light colors. This study aimed to investigate how different intensities of RL affect the performance, behavior and welfare of broilers. RL treatments were T1 = high intensity (320 lux), T2 = medium intensity (20 lux); T3 = dim intensity (5 lux), T4 = control/white light at (20 lux) provided on 20L:4D schedule and T5 = negative control; 12 hours dark: 12 hours day light. Cobb strain broilers were used in a Complete Randomize Design with 6 replicates. WG, water/feed intake, feed conversion ratio (FCR), mortality, behavior and welfare were assessed. At 35 d, significantly (p<0.05) highest body weight ($2,147.06g{\pm}99$) was recorded by T3. Lowest body weight ($1,640.55g{\pm}56$) and FCR (1.34) were recorded by T5. Skin weight was the only carcass parameter showed a significant (p<0.05) influence giving the highest (56.2 g) and the lowest (12.6 g) values for T5 and T1 respectively. Reduced welfare status indicated by significantly (p<0.05) higher foot pad lesions, hock burns and breast blisters was found under T3, due to reduced expression of behavior. Highest walking ($2.08%{\pm}1%$) was performed under T1 in the evening during 29 to 35 days. Highest dust bathing ($3.01%{\pm}2%$) was performed in the morning during 22 to 28 days and highest bird interaction (BI) ($4.87%{\pm}4%$) was observed in the evening by T5 during 14 to 21 days. Light $intensity{\times}day$ $session{\times}age$ interaction was significantly (p<0.05) affected walking, dust bathing and BI. Light intensity significantly (p<0.05) affected certain behaviors such as lying, eating, drinking, standing, walking, preening while lying, wing/leg stretching, sleeping, dozing, BI, vocalization, idling. In conclusion, birds essentially required provision of light in the night for better performance. Exposed to 5 lux contributed to higher WG, potentially indicating compromised welfare status. Further researches are suggested to investigate RL intensity based lighting regimen that favors for both production and welfare of Broilers.

Effect of Partial Substitution of Dietary Spray-dried Porcine Plasma or Fishmeal with Soybean and Shrimp Protein Hydrolysate on Growth Performance, Nutrient Digestibility and Serum Biochemical Parameters of Weanling Piglets

  • Sun, Zhantian;Ma, Qiugang;Li, Zhongrong;Ji, Cheng
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.7
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    • pp.1032-1037
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    • 2009
  • The present experiment was conducted to study the effects of partial replacement of spray-dried porcine protein (SDPP) or fish meal with soybean and shrimp protein hydrolysate (SSPH) on growth performance, nutrient digestibility and serum biochemical parameters in weaned pigs. Two hundred and forty 21${\pm}$2 d old pigs ((Pietrain${\times}$Duroc)${\times}$(Landrace${\times}$Large Yorkshire)) with initial weight of 6.9${\pm}$0.5 kg were randomly allocated to five dietary treatments with six replicates per treatment and eight piglets per replicate. The control diet (T1) contained 2% SDPP and 6% fishmeal, and SDPP for experimental diets T2 and T3 was replaced with 1% and 2% SSPH, respectively, on an iso-nitrogenous basis. The fishmeal for experimental diets T4 and T5 was replaced with 1% and 2% SSPH, respectively, also on an iso-nitrogenous basis. The experimental period was 21 days. The results showed that weaned piglets fed the diets containing 1% and 2% SSPH as a replacement for SDPP had similar average daily gain (ADG), average daily feed intake (ADFI), feed/gain (F/G), diarrhea rate and serum biochemical indices e.g. blood urea nitrogen (BUN), total serum protein (TP), albumin to globulin ratio (A/G), globulin (GLO), serum glucose (GLU), and immunoglobulin G (IgG) to those fed the control diet during 0-10 d and 0-21 d of the experiment. The substitution of 1% SSPH on an iso-nitrogenous basis for fish meal appeared to be beneficial for ADG (p = 0.59) and ADFI (p = 0.23) of piglets during the overall period. The digestibility of calcium was higher (p<0.01) in pigs fed diets containing SSPH than on the control diet. Addition of 1% SSPH on an iso-nitrogenous basis for fish meal could increase the digestibilities of dry matter and energy of the diet. Dietary replacement of fish meal with 1% and 2% SSPH had no effect on the concentrations of BUN, TP, A/G, GLO, GLU, and IgG. In conclusion, dietary SDPP or fish meal could partially replace SSPH without any adverse effect on growth performance, nutrient digestibility and serum biochemical parameters in weaned piglets.

Variance Components and Genetic Parameters for Milk Production and Lactation Pattern in an Ethiopian Multibreed Dairy Cattle Population

  • Gebreyohannes, Gebregziabher;Koonawootrittriron, Skorn;Elzo, Mauricio A.;Suwanasopee, Thanathip
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.9
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    • pp.1237-1246
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    • 2013
  • The objective of this study was to estimate variance components and genetic parameters for lactation milk yield (LY), lactation length (LL), average milk yield per day (YD), initial milk yield (IY), peak milk yield (PY), days to peak (DP) and parameters (ln(a) and c) of the modified incomplete gamma function (MIG) in an Ethiopian multibreed dairy cattle population. The dataset was composed of 5,507 lactation records collected from 1,639 cows in three locations (Bako, Debre Zeit and Holetta) in Ethiopia from 1977 to 2010. Parameters for MIG were obtained from regression analysis of monthly test-day milk data on days in milk. The cows were purebred (Bos indicus) Boran (B) and Horro (H) and their crosses with different fractions of Friesian (F), Jersey (J) and Simmental (S). There were 23 breed groups (B, H, and their crossbreds with F, J, and S) in the population. Fixed and mixed models were used to analyse the data. The fixed model considered herd-year-season, parity and breed group as fixed effects, and residual as random. The single and two-traits mixed animal repeatability models, considered the fixed effects of herd-year-season and parity subclasses, breed as a function of cow H, F, J, and S breed fractions and general heterosis as a function of heterozygosity, and the random additive animal, permanent environment, and residual effects. For the analysis of LY, LL was added as a fixed covariate to all models. Variance components and genetic parameters were estimated using average information restricted maximum likelihood procedures. The results indicated that all traits were affected (p<0.001) by the considered fixed effects. High grade $B{\times}F$ cows (3/16B 13/16F) had the highest least squares means (LSM) for LY ($2,490{\pm}178.9kg$), IY ($10.5{\pm}0.8kg$), PY ($12.7{\pm}0.9kg$), YD ($7.6{\pm}0.55kg$) and LL ($361.4{\pm}31.2d$), while B cows had the lowest LSM values for these traits. The LSM of LY, IY, YD, and PY tended to increase from the first to the fifth parity. Single-trait analyses yielded low heritability ($0.03{\pm}0.03$ and $0.08{\pm}0.02$) and repeatability ($0.14{\pm}0.01$ to $0.24{\pm}0.02$) estimates for LL, DP and parameter c. Medium heritability ($0.21{\pm}0.03$ to $0.33{\pm}0.04$) and repeatability ($0.27{\pm}0.02$ to $0.53{\pm}0.01$) estimates were obtained for LY, IY, PY, YD and ln(a). Genetic correlations between LY, IY, PY, YD, ln(a), and LL ranged from 0.59 to 0.99. Spearman's rank correlations between sire estimated breeding values for LY, LL, IY, PY, YD, ln(a) and c were positive (0.67 to 0.99, p<0.001). These results suggested that selection for IY, PY, YD, or LY would genetically improve lactation milk yield in this Ethiopian dairy cattle population.

Estimation of genetic parameters of the productive and reproductive traits in Ethiopian Holstein using multi-trait models

  • Ayalew, Wondossen;Aliy, Mohammed;Negussie, Enyew
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.11
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    • pp.1550-1556
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    • 2017
  • Objective: This study estimated the genetic parameters for productive and reproductive traits. Methods: The data included production and reproduction records of animals that have calved between 1979 and 2013. The genetic parameters were estimated using multivariate mixed models (DMU) package, fitting univariate and multivariate mixed models with average information restricted maximum likelihood algorithm. Results: The estimates of heritability for milk production traits from the first three lactation records were $0.03{\pm}0.03$ for lactation length (LL), $0.17{\pm}0.04$ for lactation milk yield (LMY), and $0.15{\pm}0.04$ for 305 days milk yield (305-d MY). For reproductive traits the heritability estimates were, $0.09{\pm}0.03$ for days open (DO), $0.11{\pm}0.04$ for calving interval (CI), and $0.47{\pm}0.06$ for age at first calving (AFC). The repeatability estimates for production traits were $0.12{\pm}0.02$, for LL, $0.39{\pm}0.02$ for LMY, and $0.25{\pm}0.02$ for 305-d MY. For reproductive traits the estimates of repeatability were $0.19{\pm}0.02$ for DO, and to $0.23{\pm}0.02$ for CI. The phenotypic correlations between production and reproduction traits ranged from $0.08{\pm}0.04$ for LL and AFC to $0.42{\pm}0.02$ for LL and DO. The genetic correlation among production traits were generally high (>0.7) and between reproductive traits the estimates ranged from $0.06{\pm}0.13$ for AFC and DO to $0.99{\pm}0.01$ between CI and DO. Genetic correlations of productive traits with reproductive traits were ranged from -0.02 to 0.99. Conclusion: The high heritability estimates observed for AFC indicated that reasonable genetic improvement for this trait might be possible through selection. The $h^2$ and r estimates for reproductive traits were slightly different from single versus multi-trait analyses of reproductive traits with production traits. As single-trait method is biased due to selection on milk yield, a multi-trait evaluation of fertility with milk yield is recommended.

In vitro Effect of High Osmolality on Plasma Membrane Activities in the Spermatozoa (In Vitro 고삼투압이 정자 원형질막의 Protein Tyrosine Phosphorylation에 미치는 영향)

  • 오영근;장재호;최인호;정노팔;신형철;곽병주
    • Biomedical Science Letters
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    • v.6 no.4
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    • pp.237-244
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    • 2000
  • It has been reported that plasma membrane activity of the spermatozoa may be susceptible to be influenced by extracellular osmolality and such membranous changes involve infracellular molecular changes, special regard to the structure of membranous lipids, and the accompanying ion-channel of which are closely related with their fluidity of $Ca^{2+}$ and HCO$^{-}_{3}$. It is of common recognition that a certain kind of sterol acceptor player an important to induce lipid fluctuation of the sperm plasma membrane which have been influenced by BSA administration and came in effect to outflow of cholesterol from the spermatozoa and resulted in changes of ionic fluidity to facilitate adenylyl cyclase, and to induce protein tyrosine phosphorylation by increase of cAMP and activation of PKA. Thus it seems likely that an augmentation of the acrosomal reaction is closely related with protein tyrosine phosphorylation. The following experimental results were obtained in the present study; Under the high osmolality conditions, the spermatozoa motility declined significantly and the structural change of the plasma membrane diminished to confirm that the response degrees to the osmolality depended upon the water transfer volume through the plasma membrane and the changes of cellular volume. Those experimental results suggest that a physiological parameter such as low temperature condition played an important role for presentation of spermatozoa and that inducement of spermatozoa activation for reinforcement of protein tyrosine phosphorylation. On the other hand, it seemed likely that the BSA administration as one of sterol accepters might represent a key role also under the high osmolality condition and their result also suggests that osmolality change, special regard to high osmolality condition may play an important role also in the processes of signal transmission.

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Design of a synchronization controller for non-rail mobile rack using repetitive control method (반복제어기법을 이용한 무궤도 이동랙 동기화제어기 설계)

  • Kim, Hwan-Seong;Park, Jin;Ha, Yun-Su
    • Journal of Advanced Marine Engineering and Technology
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    • v.40 no.6
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    • pp.527-534
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    • 2016
  • The non-rail mobile rack, which is used for cargo storage, can improve the storage capacities of logistics centers. Furthermore, it has the advantage that it can be used in traditional logistics centers without making any changes or renovation, such as installing rails. However, when the rack is operated by separated drive actuators mounted on the left and the right wheels, precise position control of the wheels is necessary even if the unbalanced cargo weight on the rack would affect the control. Therefore, internal synchronization control for position tracking between the left and right wheels on the non-rail mobile rack is necessary in this study. In addition, external synchronization control for realizing the same straight movements between mobile racks is necessary. For the internal and the external synchronization control, we propose a synchronization control algorithm based on the repetitive control theory. An internal synchronization control algorithm with repetitive control theory requires the application of the robust servo control method owing to parameter variations. In this case, we can set up the gains for the robust servo control system by considering the cargo variations on the mobile rack. Furthermore, for developing the external synchronization control algorithm, we use a double repetitive control system to perform synchronization control between mobile racks. The efficiency of the proposed control algorithm will be verified by simulation and experimental results. The proposed algorithm can be easily applied in the industry.