• The KIPS Transactions:PartB
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• v.19B no.3
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• pp.155-164
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• 2012

This study aims to identify the multidimensional variables and sub-variables and study their relative weight in music recommender systems when maximizing the rating function R. To undertake the task, a optimization formula and variables for a research model were derived from the review of prior works on recommender systems, which were then used to establish the research model for an empirical test. With the research model and the actual log data of real customers obtained from an on line music provider in Korea, multiple regression analysis was conducted to induce the optimal correlation of variables in the multidimensional model. The results showed that the correlation value against the rating function R for Items was highest, followed by Social Relations, Users and Contexts. Among sub-variables, popular music from Social Relations, genre, latest music and favourite artist from Items were high in the correlation with the rating function R. Meantime, the derived multidimensional recommender systems revealed that in a comparative analysis, it outperformed two dimensions(Users, Items) and three dimensions(Users, Items and Contexts, or Users, items and Social Relations) based recommender systems in terms of adjusted $R^2$ and the correlation of all variables against the values of the rating function R.

• Journal of Life Science
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• v.19 no.1
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• pp.15-20
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• 2009

Uncoupling protein 3 (UCP3) is a mitochondrial protein that is expressed predominantly in skeletal muscle. It may play a role in altering metabolic function. However, its major physiological roles are not fully understood. Recently de novo expression of UCP3 in rat liver by fenofibrate was reported. We also reported previously that fenofibrate-induced de novo expression of UCP3 contributes to reduction of adipose tissue in obese rats. In the present study, we investigated that ienofibrate-induced expression of UCP3 in rat liver is related with metabolic function such as body weight and hepatic lipid content by time-dependent manner in high-fat diet rats. Eight-week-old male Sprague-Dawley rats were randomly divided into two groups; the high fat diet group (HF, n=16) and fenofibrate-treated high fat diet group (HFF, n=16). The mRNA expression of hepatic UCP3 was detected as early as 1 week of fenofibrate treatment by quantitative real-time PCR and the amount of mRNA was increased time-dependently. The mean body weight of the HFF group was significantly less com. pared with the HF group after 6 weeks of fenofibrate treatment, even though there was no difference of food intake between the two groups. Rectal temperature was increased during 4 to 6 weeks of fenofibrate treatment and body weight was decreased after 6 weeks of treatment. These results were corresponded with the increased amount of the expression of UCP3 mRNA and protein. We suggest that de novo expression of hepatic UCP3 is increased time-dependently with fenofibrate treatment and that the amount of expression is correlated with metabolic function.

• The Journal of Internal Korean Medicine
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• v.31 no.2
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• pp.314-330
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• 2010

Objective : This study was performed to investigate the anti-fibrogenic effect and changes of inflammation-related genes by YBR I and YBR II (YBR I: Arteisiae Capillaris Herba, Atractylodis Rhizoma Alba, Hoelen/ YBR II: YBR I +Sanguisorbae Radix, Biotae Cacumen, Cirsii Japonici Herba) on HSC(hepatic stellate cells)-T6 and TAA-induced rat liver tissue. Materials and Methods : HSC-T6 were treated with various concentrations of distilled-water extract YBR I and YBR II extract for 24, 48 and 72 hours. After the treatment, cell viability, proliferation, procollagen levels and IL-6 levels were measured by using MTT Assay, BrdU Assay, Procollagen Type 1 C-peptide EIA kit, and Murine IL-6 ELISA Development kit. Rat liver fibrosis was induced by intraperitoneal TAA injection of 150mg/kg 3 times a week for 6 weeks. After the treatment, body weight, liver & spleen weights, liver function test, complete blood cell count and change of portal pressure were studied. In addition, gene expressions of ASMA, IL-6, MMP-2, TIMP-1 and TIMP-2, all of which are known to be associated with liver fibrosis, were analyzed by using Real-Time PCR. After YBR I and YBR IItreatment, percentages of collagen in TAA-induced rat liver tissue were measured. Results : The viability and proliferation of the HSC-T6 decreased as the concentration increased. The production of procollagen decreased as the concentration increased. The production of IL-6 was little influenced by YBR I and YBR II. There was no difference in rat body weight between the TAA-only group and the YBR groups. Compared with rat liver weight of TAA-only group, that of the YBR groups increased. In the YBR I group, the serum level of AST elevated by TAA injection significantly decreased and in the YBR I and II group, the serum level of ALP and ALT elevated by TAA injection decreased. In the YBR I group, white blood cell count elevated by TAA injection decreased but platelets increased. In the YBR I group, the portal pressure elevated by TAA injection significantly decreased. Decreases in the gene expression of ASMA and MMP-2 were observed in the YBR I group. The gene expression of IL-6 was little influenced by YBR I and YBR II -treated groups. In the histological finding, TAA injections caused severe fibrosis, but YBR I and YBR II treatment significantly reduced the amounts of hepatic collagens. Conclusions : These results suggest that YBR I and II have inhibitory effects on the hepatic fibrogenesis.

• Journal of Korean Society of Transportation
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• v.21 no.1
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• pp.103-113
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• 2003

This paper shows alternative route search and preference route search for the traffic route search, and proposes the use of the fuzzy non-additive controller by the application of AHP(analytic hierarchy process). It is different from classical route search and notices thinking method of human. Appraisal element, weight of route is extracted from basic of the opinion gathering for the driving expert and example of route model was used for the finding of practice utility. Model evaluation was performed attribute membership function making of estimate element, estimate value setting, weight define by the AHP, non additive presentation of weight according to $\lambda$-fuzzy measure and Choquet fuzzy integral. Finally, alternative route search was possible to real time traffic route search for the well variable traffic environment, and preference route search showed reflection of traffic route search disposition for the driver individual. This paper has five important meaning. (1)The approach is similar to the driver's route selection decision process. (2)The approach is able to control of route appraisal criteria for the multiple attribute. (3)The approach makes subjective judgement objective by a non additive. (4)The approach shows dynamic route search for the alternative route search. (5)The approach is able to consider characteristics of individual drivers attributed for the preference route search.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.620-626
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• 2004

For general nonlinear processes, it is difficult to control with a linear model-based control method and nonlinear controls are considered. Among the numerous approaches suggested, the most rigorous approach is to use dynamic optimization. Many general engineering problems like control, scheduling, planning etc. are expressed by functional optimization problem and most of them can be changed into dynamic programming (DP) problems. However the DP problems are used in just few cases because as the size of the problem grows, the dynamic programming approach is suffered from the burden of calculation which is called as 'curse of dimensionality'. In order to avoid this problem, the Neuro-Dynamic Programming (NDP) approach is proposed by Bertsekas and Tsitsiklis (1996). To get the solution of seriously nonlinear process control, the interest in NDP approach is enlarged and NDP algorithm is applied to diverse areas such as retailing, finance, inventory management, communication networks, etc. and it has been extended to chemical engineering parts. In the NDP approach, we select the optimal control input policy to minimize the value of cost which is calculated by the sum of current stage cost and future stages cost starting from the next state. The cost value is related with a weight square sum of error and input movement. During the calculation of optimal input policy, if the approximate cost function by using simulation data is utilized with Bellman iteration, the burden of calculation can be relieved and the curse of dimensionality problem of DP can be overcome. It is very important issue how to construct the cost-to-go function which has a good approximate performance. The neural network is one of the eager learning methods and it works as a global approximator to cost-to-go function. In this algorithm, the training of neural network is important and difficult part, and it gives significant effect on the performance of control. To avoid the difficulty in neural network training, the lazy learning method like k-nearest neighbor method can be exploited. The training is unnecessary for this method but requires more computation time and greater data storage. The pH neutralization process has long been taken as a representative benchmark problem of nonlin ar chemical process control due to its nonlinearity and time-varying nature. In this study, the NDP algorithm was applied to pH neutralization process. At first, the pH neutralization process control to use NDP algorithm was performed through simulations with various approximators. The global and local approximators are used for NDP calculation. After that, the verification of NDP in real system was made by pH neutralization experiment. The control results by NDP algorithm was compared with those by the PI controller which is traditionally used, in both simulations and experiments. From the comparison of results, the control by NDP algorithm showed faster and better control performance than PI controller. In addition to that, the control by NDP algorithm showed the good results when it applied to the cases with disturbances and multiple set point changes.

• Korean Journal of Applied Biomechanics
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• v.24 no.1
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• pp.35-42
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• 2014

Tendon elasticity is an important factor affecting muscle function and thus human movements. It has been reported that the mechanical properties of tendon are adaptable to external loading condition. Based on the adaptability of muscle and tendon to external loading conditions, one can assume that there might be an optimum ratio between muscle strength and tendon stiffness. The present study aimed to investigate whether there is correlation between plantar flexor muscle strength and stiffness of the achilles tendon (AT). Twenty two male subjects (age: $23.2{\pm}1.5yrs$, height: $175.5{\pm}6.2cm$, weight: $75.4{\pm}9.8kg$) performed maximum voluntary isometric plantarflexion on a custom-built dynamometer and muscle-tendon junction of the medial gastrocnemius muscle was simultaneously monitored using a real-time ultrasound imaging machine. The averages of muscle force and tendon stiffness were $366.38{\pm}79.37N$, $35.34{\pm}10.42N/mm$, respectively. Significant positive correlation was observed between muscle strength and tendon stiffness (r=0.8507), indicating that the muscle force is proportional to tendon stiffness. The results might have been used in computational modeling and criterion of training progress level in the fields of training and rehabilitation.

• Nutrition Research and Practice
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• v.10 no.5
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• pp.477-486
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• 2016

BACKGROUND/OBJECTIVES: Consumption of pine nut oil (PNO) was shown to reduce weight gain and attenuate hepatic steatosis in mice fed a high-fat diet (HFD). The aim of this study was to examine the effects of PNO on both intestinal and hepatic lipid metabolism in mice fed control or HFD. MATERIALS/METHODS: Five-week-old C57BL/6 mice were fed control diets containing 10% energy fat from either Soybean Oil (SBO) or PNO, or HFD containing 15% energy fat from lard and 30% energy fat from SBO or PNO for 12 weeks. Expression of genes related to intestinal fatty acid (FA) uptake and channeling (Cd36, Fatp4, Acsl5, Acbp), intestinal chylomicron synthesis (Mtp, ApoB48, ApoA4), hepatic lipid uptake and channeling (Lrp1, Fatp5, Acsl1, Acbp), hepatic triacylglycerol (TAG) lipolysis and FA oxidation (Atgl, Cpt1a, Acadl, Ehhadh, Acaa1), as well as very low-density lipoprotein (VLDL) assembly (ApoB100) were determined by real-time PCR. RESULTS: In intestine, significantly lower Cd36 mRNA expression (P<0.05) and a tendency of lower ApoA4 mRNA levels (P = 0.07) was observed in PNO-fed mice, indicating that PNO consumption may decrease intestinal FA uptake and chylomicron assembly. PNO consumption tended to result in higher hepatic mRNA levels of Atgl (P = 0.08) and Cpt1a (P = 0.05). Significantly higher hepatic mRNA levels of Acadl and ApoB100 were detected in mice fed PNO diet (P<0.05). These results suggest that PNO could increase hepatic TAG metabolism; mitochondrial fatty acid oxidation and VLDL assembly. CONCLUSIONS: PNO replacement in the diet might function in prevention of excessive lipid uptake by intestine and improve hepatic lipid metabolism in both control diet and HFD fed mice.

• Journal of fish pathology
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• v.29 no.1
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• pp.25-33
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• 2016

In human medicine, circulating microRNAs have been successfully utilized as early biomarkers for various abnormalities and disease states. Vertebrate miR-122 is a liver-specific microRNA which is expressed almost solely in hepatocytes and plays an important role in the regulation of hepatocyte function. In this study, to evaluate the potential utility of circulating miR-122 as a biomarker for liver injury in olive flounder (Paralichthys olivaceus), fish were orally intubated with two doses of acetaminophen (500 mg/kg or 1.000 mg/kg of body weight), and the expression of miR-122 in serum was quantified using real time-PCR. Histological change in liver, and the enzymatic activity of glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) were also analyzed. The results showed that miR-122 was higher in acetaminophen administered groups compared to control group. The histopathological effect of acetaminophen on olive flounder liver was not distinct. The serum level of GPT and GOT was increased within 2 folds compared to control group by acetaminophen administration. However, the serum miR-122 level was increased more than 3 or 4 folds compared to the control group by administration of 1000 mg/kg of acetaminophen. These results suggest the possible use of miR-122 as an indicator of liver injury in olive flounder, even when histopathological effects are not distinctive.

• Computational Structural Engineering
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• v.10 no.4
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• pp.315-325
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• 1997

This paper describes the application of discretized continuum-type optimality criteria (DCOC) and the development of optimum design program for the multispan partially prestressed concrete beams. The cost of construction as objective function which includes the costs of concrete, prestressing steel, non-prestressing steel and formwork is minimized. The design constraints include limits on the maximum deflection, flexural and shear strengths, in addition to ductility requirements, and upper and lower bounds on design variables as stipulated by the design Code. Based on Kuhn-Tucker necessary conditions, the optimality criteria are explicitly derived in terms of the design variables-effective depth, eccentricity of prestressing steel and non-prestressing steel ratio. The prestressing profile is prescribed by parabolic functions. The self-weight of the structure is included in the equilibrium equation of the real system, as is the secondary effect resulting from the prestressing force. An iterative procedure and computer program for updating the design variables are developed. Two numerical examples of multispan PPC beams with rectangular cross-section are solved to show the applicability and efficiency of the DCOC-based technique.

• International Journal of Highway Engineering
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• v.11 no.1
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• pp.47-58
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• 2009

Calibrating toll roads of highway networks needs additional weights within volume delay functions not like other general highway lints. However, current methods assigning additional weights in the volume delay function of toll roads are not sufficiently enough to predict real toll road volumes measured, since it does not consider discounting rates and an extra charges. This study develops methods to improve relevant and reliable volume delay functions. Suggested ideas include a method of weighting volume delay functions considering a value of time of vehicle types, a method of weighting volume delay functions considering lane distributions of vehicles, and a method of weighting volume delay functions considering percentages of link lengths per a number of lanes of toll roads. It is found that the method of weighting volume delay functions considering lane distributions of vehicles show most reliable and appropriate results, while the first method shows overestimation and the third method does underestimation of highway link volumes. In terms of assignment methods, total OD equilibrium assignment shows better results than PCU based assignment.