• Proceedings of the KSR Conference
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• 2005.11a
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• pp.170-175
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• 2005

In this study, experimental and theoretical methods were applied to understand brake squeal noise VVVF rolling stock on tracks. Trailer cars needed to payed a particular attention, because they were the major source of brake noise. VVVF rolling stocks for lines no 1 of the subway system in Seoul were used for experimental analyses. In order to study brake squeal noise, a dynamometer test at the S&T Brake, Co., which was a manufacturer of brake pads had performed. For measuring vibration and noise, vibration tests of brake parts (brake lining, brake lining head, back plates, etc.) at the SNUT were executed. Also, vibration tests of disc assembly and lining block at the heavy maintenance shop of the Gunja depot were performed. The modal analyses by using an ANSYS which was one of the CAE commercial program were simulated to know the relationship to the mechanism of brake noise. On the based of the tests and the simulations it was found that specific frequencies of the brake parts affected squeal noise, and improvements for reducing squeal noise were proposed.

• Korean Journal of Organic Agriculture
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• v.20 no.1
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• pp.71-80
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• 2012

This experiments was conducted to investigate the influence on growth of rye, triticale with legume and investigated their productivity, feed value and stock carrying capacity in order to select the appropriate forage species in the central region of Korea. In the results, Rye+Red clover showed 5.2ton/ha of dry matter yield. But there was no significant difference with Triticale+Red clover and Rye in upland field. In paddy field, Rye+Hairy vetch showed 5.2ton/ha, but there was no significant difference with Triticale+Hairy vetch and Rye. Mixture effects with Rye, Triticale and Red clover, Hairy vetch by relative yield were more than 1.00 compared to monoculture, and their mixture effect was recognized in upland and paddy field. Relative feed value was highest in the applications of Triticale mixture in upland and paddy field. The average value of $K_{CP}$ and $K_{TDN}$ showed the highest one as 2.75head/ha/yr in Rye+Red clover in upland field and 2.84head/ ha/yr in Triticale+Hairy vetch in paddy field. According to the results, Rye+Red clover in upland field and Triticale+Hairy vetch in paddy field were considered to be the most appropriate winter forage crops for the central region of Korea in terms of productivity, feed value and stock carrying capacity.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.59-70
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• 2013

As people invest most of their asset in real estate, there is high interest in changing in housing and real estate prices in the future for a digital economy. Various variables are affecting the housing and real estate market. Among them, four variables : households, productive population, interest rate and index price are chosen and analyzed representatively. This study is aimed to build decision model of apartment prices in Seoul empirically. From the analysis result the stock index is the only variable which is significant statistically to apartments in Seoul. From this study, the households and productive population show the same direction as shown in the previous studies before but not significant statistically. Among the independent variables, the stock index is chosen as a major variable of determinant of Seoul apartment price. From the result of the research, prediction of stock market should be preceded to forecast the movement of housing and real estate market in the future.

• Korean Journal of Rural Living Science
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• v.9 no.1
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• pp.43-54
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• 1998

This study attempted to investigate the factors affecting financial status of the rural middle-aged and old-aged household. The results shelved that the significant variables which influenced on the probability of financial security measured by consumption to income ratio were sex and education level of the household head, family size, total income, total expenditure and total assets. The most influential variables on the probability of financial security measured by liquidity ratio was liquid assets, and total assets. Education level of the household head. liquid assets, total assets, and total debt had significant effects on the probability of financial security estimated by debt burden ratio. Among the economic variables, only liquid asset had significant negative effects on the probability of financial security assessed by the capital stock ratio.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.29 no.10 s.241
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• pp.1416-1429
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• 2005

In order to meet the increasing competitive pressures coupled with higher demands for component quality, whirling machines have been at the cutting edge of the automobile industry for more than 25 years. The hard whirling process can save on machining time and operation elimination. Hard whirling is done dry, without coolant. The chips carry away nearly all of the heat during cutting, leaving the workpiece cool and minimizing any thermal geometry variations. The surface finish and profile accuracy are close to grinding quality. Whirling machines usually consist of four major parts; 1) loading system that requires the necessary axial speeds, 2) head stock that needs high precision clamping and positioning system at the chuck and tailstock, 3) whirling unit that demands the high cutting speeds and cutting power fer cutting deep thread profiles and 4) unloading system that requires an easy workpiece unloading. Also, capabilities of the whirling machine can be improved by attaching a vision system to the machine. Most of whirling machines in Korean automobile industry are imported from the Leistritz company, Germany and the Hasegawa company, Japan. Tn this paper, a basic research will be performed to improve and enhance the existing whirling machines. Finally, a new Korean whirling machine will be proposed and developed.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.1
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• pp.104-111
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• 2017

This research focuses on simulation and visualization of flow field characteristics inside a centrifugal pump. The 3D numerical analysis was carried out by using a numerical CFD tool, addressing a Reynolds Average Navier-Stock code with a standard k-${\varepsilon}$ two-equation turbulence model. The simulation accounts for friction head loss due to rough walls at suction, impeller, discharge areas and volumetric head loss at impeller wear ring. A comparison of performance curves between simulation and experimentation is included, and it reveals a same trend of those results with a small difference of maximum 5 %. At best efficiency point, velocity vectors are smooth but it changes significantly under off-design point, a strong recirculation appears at the outlet of impeller passages near tongue area. A relatively uniform preassure distribution was observed around the impeller in despite of the tongue. Within the volute, because of its geometry, spiral vortexes formed, proving that the flow field in this region was relatively turbulent and unsteady.

• Journal of Veterinary Clinics
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• v.16 no.2
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• pp.428-438
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• 1999

A study was conducted to estimate cost of major dairy cattle diseases. Forty (n=40) of the 167 dairy herds in Gyeongnam (Chinju) area were stratified and selected randomly for participation in the national animal health monitoring system. Gyeongsnag University veterinarians, Gyeongnam Livestock Promotion Institute veterinarians and clinic veterinarian visited each herd once a month for a total periods of 12 months. At a each visit data on disease, production, management, finance, treatments, preventive activities, animal events, and any other relevant events were collected. Monthly and annual cost estimates of disease treatment were in computed in each herd and stratum(including cost of prevention). Results were expressed as cost per head and given separately for cows, young stock, and calves. In cows, the most expensive seven diseases entities (from the most to the least) were : (1) clinical mastitis; (2) breeding problems; (3)gastrointestinal problems; (4) multiple system problem; (5) birth problems; (6) metabolic/nutritional disease; (7) lameness. In young stock, the most costly disease were the multiple system problems, breeding problems, respiratory disease, gastrointestinal disease, and lameness. In calves, the most costly disease problems were gastrointestinal problems, respiratory disease, integumental, multiple system problems, and metabolic/nutritional problems.

• Korean journal of food and cookery science
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• v.6 no.2
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• pp.15-26
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• 1990

The material used for the experimental analyses and sensory evaluation of this thesis is 8 Bastards. 4 Bastards are used as Sample A and the other 4 Bastards are used as Sample B. Sample A is the broth from 100 grams of flesh and spinal bones, boiled for (1) 15 minutes, (2) 30 minutes, (3) 60 minutes, and (4) 120 minutes. Sample B is the broth from 100 gram of head and spinal bones, boiled for (1) 15 minutes, (2) 30 minutes, (3) 60 minutes, and (4) 120 minutes. The nutrients analyzed for this thesis are (1) free amino acid, (2) total N, and (3) minerals (Ca, P, Na, K, Zn). The results of the experimental analyses and sensory evaluation of Bastards broth with various boiling time are follows: (1) The total amounts of free amino-acid and total N in the broth are the greatest when boiled for 15 minutes, in both sample A and sample B. (2) The amounts of minerals in the broth increase as time increases. (3) The results of the sensory evaluation show that the subjects prefer the taste of the stock boiled for 120 minutes with regard to sample A, but that they prefer the taste of the stock boiled for 15 minutes with regard to sample B.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.39 no.5
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• pp.1-6
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• 2007

Formation which is one of the most fundamental characteristic of paper quality is affected by a number of variables. Fiber flocculation in the headbox has been recognized as the most important variable influencing formation. Consistency and crowding number of head box stock are known to represent the flocculation potential of stocks. The effects of consistency and crowding number on paper formation were studied by measuring the flocculation of fiber suspensions. Increasing consistency increased the degree of fiber flocculation. Especially the consistency of long fiber fraction was the most crucial factor of flocculation. Tensile strength of handsheets was furnish dependent rather than flocculation dependent. Crowding number of a furnish can be used for the characterization of stock flocculation.

• Fisheries and Aquatic Sciences
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• v.22 no.6
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• pp.12.1-12.8
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• 2019

Background: Wild fish populations stock is continuously diminishing in the Indo-Ganges river basin, and the population status of most fishes is unidentified. The identification of the population status and the conservation of commercially important and endemic wild fish populations in this region are crucial for the management. The aim of this paper was to identify the population status of Cirrhinus reba, a promising aquaculture but vulnerable species in the Indo-Ganges river basin in Bangladesh. Methods: C. reba samples were collected from four isolated populations of the Brahmaputra (n = 30), the Padma (33), the Karatoya (31), and the Jamuna Rivers (30) in Bangladesh, and the population status was evaluated using morphometric and landmark comparisons. Data were analyzed with the Kruskal-Wallis test, univariate analysis, discriminant function analysis, and the formation of a dendrogram. Results: Three meristic characters (Pectoral fin rays, caudal fin rays, scale in lateral lines), four morphometric characters (head length, pre-orbital length, post-orbital length, maximum body depth), and truss measurement (4-7) were significantly different among the stocks. The step-wise discriminant function analysis retained 15 variables from morphometric and landmark measurements that significantly differentiated the populations based on the constructed DFI and DFII. Discriminate function analysis also showed that 91.2% of the original groups were classified into their correct samples. The cluster analysis of Euclidean distances placed the Jamuna population in one cluster and the Brahmaputra, the Padma, and the Karatoya populations in the second one. Conclusion : Morphological differences among the stock were probably due to different ancestral origin. This is the first report about population status of C. reba in their natural habitat of the Indian subcontinent. Further genetic studies and the evaluation of environmental impact on C. reba populations in Bangladesh are suggested to support our findings.