• Journal of the Ergonomics Society of Korea
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• v.24 no.2
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• pp.65-70
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• 2005

Evaluation of repetitiveness for upper extremity intensive tasks is essential to determine the level of risk for upper extremity musculoskeletal disorders at the workplace. However, experimental data available to establish the acceptable levels of repetitiveness for various postures and forces is lacking. The present study examined the maximum acceptable frequencies(MAFs; motions/min.) of shoulder, elbow, wrist, and index finger motions at different forces(1kgf and 4kgf for shoulder, elbow, and wrist; 0.25kgf and 1 kgf for index finger) in sitting. Seventeen right-handed males in 20s without having any history musculoskeletal disorders participated in the MAF experiment. The participants determined their MAFs for the upper extremity motions by using the self-adjustment method and their work pulse(increase in heart rate; beats/min.) and rating of perceived exertion(RPE) were measured when working at MAF. The MAFs of elbow, wrist, and index finger motions for each force level were about 2, 3, and 6 times the corresponding MAF(9 at the high force and 24 at the low force) of shoulder motion and the MAFs at the low force increased about 2 times those at the high force. The work pulses of elbow, wrist, and index finger motions for each force level were 70%, 50%, and 30% of the corresponding work pulse(17 at the high force and 12 at the low force) of shoulder motion and the work pulses at the low force were about 70 % of those at the high force. Lastly, the RPEs of the upper extremity regions were about level 3(moderate) or below.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.77-86
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• 2003

Pullorum disease due to Salmonella enterica subspecies enterica bioserovar Pullorum (S. pullorum) is reported to be an endemic disease in domestic poultry flocks. The pulsed-field gel electrophoresis (PFGE) subtyping method was used to assess the extent of genetic diversity and clonality of most of salmonella serotypes and other diverse bacterial species from animals and environmental samples in worldwide. Nowadays, PFGE has already been evaluated as a gold standards for molecular subtyping of salmonella serotypes compared with other molecular analysis methods. PFGE of XbaI digested chromosomal DNA from 23 strains of S. pullorum gave 5 distinctive pulsotypes (from SXPI to SXPV) with 5% confidence range of Dice coefficients, indicating that PFGE is very discriminative and that multiple clones of S. pullorum have been existed and diffused all of domestic poultry flocks industries since 1995. Two dominant pulsogroups (SXA & SXB) appeared as a major clones in this country, because they had consistently been recovered from diverse sources including both chicken organs and raw feed materials between 1995 and 1998. In addition, the matching percentage of PFGE profiles (PFP) among strains from both chickens and feed ingredients provides indirect evidence of the possible transmission of pullorum disease from contaminated raw feed ingredients for chicken production. In calculating of discrimination index (DI) for PFGE method by Simpson's index, DI was appeared as 0.917. Therefore, this index suggested that the present PFGE would seem to be a desirable and confident molecular typing method for S. pullorum strains. To our knowledge for pullorum disease, this is the first study to compare S. pullorum strains from chicken organs and feed samples using the PFGE.

• Korean Journal of Veterinary Research
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• v.38 no.1
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• pp.201-208
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• 1998

Piglets' diarrhea is one of the major causes of economic loss in Korean swine industry. To prevent this serious and persistant problem, we have developed systemic farm evaluation and analysis program. The program consists of the checklist and the computerized program. The items of the checklist are selected on the basis of various causative factors related with the piglets' diarrhea including sanitational status, nutritional management, or farm environment. The checklist is composed of 30 items including 6 factors on facility, 8 factors on environment, 6 factors on nutrition and 10 factors on sanitation, respectively. Minimum 1 to maximum 10 points was assigned to each item depending on level or status of farm. The scores calculated by sum of points obtained from each item could find out the problems which the farm was confronted with. To investigate the applicability of a program 150 swine farms raising over 500 heads were selected from 7 provinces throughout the country and surveyed. There were significant correlations between the piglets' diarrhea and the scores of the checklist. Based on above results we revised the checklist which consisted of 22 items including 5 factors on facility, 7 factors on environment, 3 factors on nutrition and 7 factors on sanitation. After that we composed a computerized diagram out of each point of an item which showed and indicated weak factors to be improved promptly. Our present study suggested that this newly established swine farm evaluation program would be a very efficient way to find out the problems and support the systemic control program of the piglets' diarrhea for swine farms.

• International Journal of Oral Biology
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• v.32 no.1
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• pp.1-5
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• 2007

Receptor activator of nuclear factor ${\kappa}B$ ligand (RANKL) induces osteoclast formation from hematopoietic cells via up-regulation of positive regulators, including $NF-{\kappa}B$, c-Fos, microphthalmia transcription factor (Mitf), PU.1, and nuclear factor of activated T cells (NFAT) c1. In addition to the positive regulation by these transcription factors, RANKL appears to regulate negative regulators such as MafB and inhibitors of differentiation (Ids). Ids and MafB are abundantly expressed in osteoclast precursors, bone marrowderived monocyte/macrophage lineage cells (BMMs). Expression levels of these genes are significantly reduced by RANKL during osteoclastogenesis. Overexpression of these genes in BMMs inhibits the formation of tartarate-resistant acid phosphatase (TRAP)-positive multinuclear osteoclasts by down-regulation of NFATc1 and osteoclast-associated receptor (OSCAR), which are important for osteoclast differentiation. Furthermore, reduced expression of these genes enhances osteoclastogenesis and increases expression of NFATc1 and OSCAR. Taken together, RANKL induces osteoclastogenesis via up-regulation of positive regulators as well as down-regulation of negative regulators.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.771-776
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• 1998

Synthetic oligonucleotide primers of 20 and 21 bases, respectively, were used in the polymerase chain reaction (PCR) to amplify a sequence of the mrp gene, which encodes the muramidase released protein of Streptococcus suis. Amplification was not recorded when 5 other streptococcal species were tested or when 9 different nonstreptococcal species were tested. A DNA fragment of 517bp was amplified from the genomic DNA of S suis. The lower detection limit was 100pg of the genomic DNA. The primers recognized 34 serotypes of S suis reference strains and 9 isolates from pneumonic lung, brain, nasal discharge, tonsil. This results suggest that the amplification of the mrp gene by PCR method is potential for the identification of S suis isolates.

• Biomedical Science Letters
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• v.18 no.3
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• pp.193-200
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• 2012

We examined the effects of polyamines such as putrescine and cadaverine on the biosynthesis and secretion of insulin in the mouse pancreatic ${\beta}$-cell line, MIN-6. Basal insulin secretion (BIS) and glucose-stimulated insulin secretion (GSIS) from the MIN-6 cells were significantly increased by 20 min- or 24 h-treatment with micromolar concentrations of polyamines. To determine whether the enhancement was due to increase of insulin production by polyamines, we investigated the insulin mRNA and protein production. Both insulin mRNA and protein production were found to be not significantly affected by the polyamine treatment. Next, we examined the expression of several transcription factors (TFs) related to insulin synthesis and secretion in order to identify upstream events responsible for the promotion of insulin secretion of MIN6 cells by polyamines. Of the 6 TFs tested, MafA was induced by treatment of polyamines. MafA mRNA and protein expressions increased with treatment of polyamines. Overall results suggest that cadaverine and putrescine promote the insulin secretion process rather than the insulin biosynthesis from MIN6 cells. Also MafA may be involved in the enhanced insulin secretion process. Further studies are needed to elucidate the underlying mechanisms for promotion of insulin secretion by polyamines.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.12
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• pp.2582-2589
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• 2011

This Paper proposed the prediction method of fuel consumption from vehicle diagnosis informations through OBD-II Interface. We assumed mass air flow (MAF), shor-term fuel trim (STFT), and long-term fuel trim (LTFT) had a relationship with fuel consumption. We got the output as fuel-consumption from MAF, STFT, and LTFT as input variables. We had modelling as combustion reaction equation with OBD-II data and fuel consumption data supported by automotive company in real. In order to verify the effectiveness of proposed method, 5 km real road-test was performed. The results showed that the proposed method can estimate precisely the fuel consumption from vehicle data.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.33 no.5
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• pp.514-520
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• 2009

In configuring an automated polishing system, a monitoring scheme to estimate the surface roughness is necessary. In this study, a precision polishing process, magnetic abrasive finishing (MAF), along with an in-process monitoring setup was investigated. A magnetic tooling is connected to a CNC machining to polish the surface of stavax(S136) die steel workpieces. During finishing experiments, both AE signals and force signals were sampled and analysed. The finishing results show that MAF has nano scale finishing capability (upto 8nm in surface roughness) and the sensor signals have strong correlations with the parameters such as gap between the tool and workpiece, feed rate and abrasive size. In addition, the signals were utilized as the input parameters of artificial neural networks to predict generated surface roughness. Among the three networks constructed -AE rms input, force input, AE+force input- the ANN with sensor fusion (AE+force) produced most stable results. From above, it has been shown that the proposed sensor fusion scheme is appropriate for the monitoring and prediction of the nano scale precision finishing process.

• 전자공학회논문지 IE
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• v.48 no.2
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• pp.19-25
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• 2011

This paper presented neural network modeling method using vehicle data to predict fuel consumption. To acquire data for training and testing the proposed neural network, medium-class gasoline vehicle drove at downtown and parameters measured include speed, engine rpm, throttle position sensor (TPS), and mass air flow (MAF) as input data, and fuel consumption as target data from OBD-II port. Multi layer perception network was used for nonlinear mapping between the input and the output data. It was observed that the neural network model can predict the vehicle quite well with mean squared error was $1.306{\times}10^{-6}$ for the fuel consumption.

• Journal of the Korean Society of Safety
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• v.16 no.3
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• pp.35-40
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• 2001

An internal finishing process applying Magnetic Abrasive Finishing (MAF) was proposed to produce smooth inner surfaces of tubes at a high rate. Since this process uses the tube rotation system, it has been considered applicable only to tubes which are rotatable at high speeds. Here development of the stainless tube(STS 304) rotation system to extend the scope of the application of the internal finishing process applying MAF was made. By the stainless tube(STS 304) rotation system, the abrasive magnetically attracted by the poles is rotated along the inner surface of the tube by magnetic force together with fixed poles, finishing the inner surface of the tube. The main results obtained are as follows : 1) The magnet abrasive finishing minimized influence due to external force because non-contact finishing, 2) The profile of surface roughness decreased very good in 11.4m/min range because abrasive size and speed, 3) The profile of surface roughness by flux density decreased in finishing speed 28m/min, 4) The profile of surface roughness by fled rate decreased in 0.16mm/rev and 0.18mm/rev.