• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.6D
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• pp.791-799
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• 2008

To build the system which has high utilization and usefulness for users, it is necessary to know the information type and use-demand that the use want. The purpose of this study is to forecast the preference and demand of utilization for bus information when bus information is offered through cellular phon. The accomplishments of this research are as follow : Firstly, importance on the level of individual factor and the value of change's figure can be evaluated, using preference analysis on bus information by conjoint analysis. Secondly, by establishing the use-demand model bus information using binary logit model, influence factor on whether or not the use of the user. Finally, ordered probit model was built by use behavior model in payment per call or per month of potential user of bus information. Through call times and sensitive analysis by payment methods, elasticity point, optimal payment fee, and use probability was analyzed. This study make application as basic to efficient bus information policy and to improve use rate of bus information in future because this study make it possible to get preference analysis, use-demand analysis and estimation of optimal payment fee which is reflecting various requirement in use of bus information user.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.5
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• pp.30-37
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• 2024

The valuation of infrastructure assets is typically conducted using the straight-line method, which employs the depreciated replacement cost as a basis. However, this approach has the limitation of failing to accurately reflect the actual value of the facility. In light of these considerations, the performance-based depreciation (PBD) method has been proposed as a means of evaluating the asset value of bridges on the basis of their performance, although it is not designed to take account of the environmental characteristics of individual bridges. This study proposes a hazard-performance based depreciation (HPBD) method that considers the risk level of individual bridges in the PBD method proposed in previous studies. The applicability of the proposed method was evaluated on more than 8,000 bridges. The risk factors for deterioration of bridges were selected, the hazard level of individual bridges was evaluated, and weights based on the hazard level were applied to the PBD method. The evaluation resulted in a present value comparable to that of the PBD method and a relatively high future value. It is postulated that the HPBD method, which considers the risk characteristics of individual bridges, can be used for a more reasonable evaluation and decision-making process.

• Journal of Veterinary Clinics
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• v.30 no.6
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• pp.442-448
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• 2013

The aim of the present study was to develop glycerol-free TRIS extender using glucose for dog sperm cryopreservation. We determined the appropriate concentration of glucose in glycerol-free TRIS and the exposure time in glycerol-free TRIS containing 0.3 M glucose at $4^{\circ}C$. Ejaculates of six dog sperm were cooled in glycerol-free TRIS through $4^{\circ}C$ for 100 min, cooled at $4^{\circ}C$ in TRIS with different glucose concentrations 0 M, 0.04 M, 0.1 M, 0.2 M and 0.3 M, respectively for 30 min followed by cryopreservation. After thawing at $37^{\circ}C$ for 25 sec, membrane and acrosome integrities of dog sperm were evaluated. In addition, the effect of exposure time (10, 30, 50 and 70 min) of sperm to glycerol-free TRIS containing 0.3 M glucose at $4^{\circ}C$ on progressive motility, viability, and DNA integrity following sperm cryopreservation was studied. Membrane integrity and acrosome integrity were assessed by 6-carboxyfluoresceindiacetate (6-CFDA)/propidium iodide (PI) fluorescent staining and Pisum sativum agglutinin conjugated to fluorescein isothiocyanate, respectively. DNA integrity was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling, using flow cytometry. Sperm frozen in glycerol-free TRIS supplemented with 0.2 M or 0.3 M glucose have an intact plasma membrane (CFDA+/PI-) after cryopreservation than sperm frozen in the extenders with lower glucose concentrations (p<0.05). Acrosome integrity was significantly higher in the 0.3 M group than less than 0.1 M groups (p<0.05). The sperm DNA fragmentation index did not differ according to exposure time, although progressive motility was significantly higher in the 50 min exposure group than the other groups (p<0.05). These results indicate that cryopreservation of dog sperm is feasible and yields more motile sperm following freezing and thawing in glycerol-free TRIS containing 0.3 M glucose with the exposure time for 50 min at $4^{\circ}C$.

• Current Research on Agriculture and Life Sciences
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• v.1
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• pp.179-188
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• 1983

This study was conducted to find out the most fabourable breeding structure for the maximum genetic gain of live weight, the most important economic traits of Korean native cattle, in order to achieve the improvement goals for meat productivity of the native cattle early and effectively. For estimating genetic gain and population mean changes, the following factors were investigated under the assumation that 675,000 heads of over-two-year old cows were maintained each generation and 15% of the cows were culled every year: 1. The proportion of cow population inseminated by A I bulls; 30, 40, 50, 60, 70% 2. The number of semen doses produced from each A I bull per year; 5,000, 7,000, 10,000, 15,000, 20,000 doses. 3. The average body weight of A I bulls; 480, 520, 600, 640, 680, 720kg/18 months of age. The estimated results are summarized as follows: 1. The genetic gain of live weight is affected greately by the levels of A I bulls' body weight and the genetic gain was estimated 28.66~36.31kg per generation. 2. The proportion of genetic gain from sire selection were estimated 80~90%. 3. When the average body weight of A I bulls increase 40kg per generation and more than 50% of cow population is inseminated by A I bulls, then the phenotypic mean value of live weight of bulls at the age of 18 months and heifers at the age of 2 years are expected to be reached 600kg and 520kg in the A I population; 560kg and 480kg in the whole population, respectively, after 5th generation.

• Korean Journal of Agricultural Science
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• v.13 no.1
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• pp.68-81
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• 1986

This experiment was conducted to find out the effects of the six different feeding methods on the development of body weight, testis, comb and pituitary gland, and the sexual maturity of White Plymouth Rock cockerels. From hatching to 22 weeks of age, the weights of whole body, testis, comb and pituitary gland, and the histological changes of testis and the semen characteristics were checked every other week. The results obtained in this expeniment were as follows: 1. The growth rates of the self-feeding groups were faster than those of the limited feeding groups (70 percent of the self-feeding) by about 2 weeks. The weights of testis and comb showed the most marked increase at 20 weeks of age in the self-feeding groups and at 22 weeks of age in the limited feeding groups, respectively. 2. The weights of pituitary gland from hatching to 22 weeks of age at all observation weeks were not recognized significantly among the compared groups except 4, 14 and 16 weeks of age. 3. Correlations between week of age, body weight, testis, comb and pituitary gland, in the course of 22 weeks, were highly significant. 4. The diameters of lumina and tubules in the seminiferous tubules increased very slowly until 10 weeks of age. They showed the most marked increase at 12 weeks of age in the self-feeding groups and at 14 weeks of age in the limited feeding groups, and then continueously increased until 22 weeks of age. 5. Primary spermatocytes appeared at first at 8 weeks in the all treatment groups. Secondary spermatocytes appeared at first at 10 weeks in the self-feeding groups and at 12 weeks in the limited feeding groups. At 14 weeks of age spermatids and spermatozoa were found at first in the self-feeding groups but spermatids were found in the limited feeding groups. 6. Age of the first ejaculation was between 14 and 16 weeks of age in the all treatment groups. The average semen volume and sperm concentration ranged from $0.1{\sim}0.2m{\ell}/ejaculate$ and $5.6{\sim}9.8{\times}10^8sperm/m{\ell}$ at the age of the first ejaculation but $0.30{\sim}0.35m{\ell}/ejaculate$ and $22.4{\sim}42.7{\times}10^8sperm/m{\ell}$ at the 20 weeks of age in the all treatment groups.

• Journal of Embryo Transfer
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• v.17 no.2
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• pp.137-143
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• 2002

This study was conducted to evaluate the effect of sugar kinds and combination of various sugars, and straw size and pre-freezing time on motility of post-thaw spermatozoa in canine. In general, the extender was supplemented with fructose or glucose for semen freezing. The extender used in .this study was Tris-citric acid extender (Tris-buffer) supplemented with 20％ Egg-yolk, 8％ glycerol, 1％ Equex STM paste, and 70 mM sugars such as monosaccharide (fructose and xylose) and disaccharide(trehalose). To evaluate of sugar combination, the sugars supplemented in Tris-buffer. were combined such as control (fructose, xylose, trehalose), two combinations (Fru＋Tre, Fru＋Xy1, Tre＋Xy1) and three combinations (Fru＋Tre＋Xy1). The motility after CASA analysis in Fru＋Tre＋Xy1 was higher than those in fructose, trehalose, xylose, Fru＋Tre, Fru＋Xy1, Tre＋Xy1 (69 vs. 58, 61, 50, 65, 20, 54). However, the progressive motility after CASA analysis in Fru＋Tre group was higher than those in fructose, trehalose, xylose, Fru＋Xy1, Tre＋Xy1, Fru＋Tre＋Xy1 (59％ vs. 47, 55, 42, 13, 49, 44％). The survival rate of post-thaw spermatozoa in 0.25 $m\ell$ straw for 10 min pre-freezing was significantly higher than those in 0.25 $m\ell$ straw for 10 min, 0.25 and 0.5 $m\ell$ for 5 min (80＋0.0 vs. 65＋7, 68＋16, 58＋8％; P＜0.05). The results indicated that the progressive motility of post-thaw spermatozoa in 70 mM Fru ＋Tre (two combination) following CASA analysis and 0.25 ml straw for 10 min pre-freezing time could be better for freezing of semen in canine.

• Korean Journal of Animal Reproduction
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• v.23 no.3
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• pp.205-212
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• 1999

The present study was designed to examine the effects of selenium(Se), vitamin E(Vit. E) and recombinant Bovine Somatotropin(rBST) administration on the selenium and vitamin E concentrations of blood in Hanwoo sires Hanwoo sires were randomly assigned to five groups; 1. control, 2. rBST, 0.09mg/kg body weight (BW) 3. Vit E, 1,500IU/kg BW, 4. Se 0.lmg/kg BW, 5. Vit E, 1.500IU plus Se 0.1mg/kg BW. rBST, Vit. E and Se for each experimental group were given 6 times at 15 days interval by intramuscular injection. Blood samples were collected 10 times for experimental periods, separated the serum by centrifugation, and stored at －7$0^{\circ}C$. Se and Vito E concentrations in blood were measured by fluorophotometer and HPLC. Se concentrations of blood in control, rBST, Vito E, Se and Se plus Vito E groups were 64.55, 65.50, 68.15, 73.11 and 74.09 ppb/$m\ell$, respectively. Se concentration in Vit. E plus Se group was significantly higher than in control and rBST groups (P＜0.05), but Vito E group was not significantly different in control and rBST groups(P＞0.05). The Vit. E concentrations of blood in control, rBST, Vit. E, Se and Se plus Vit. E groups were 2.27, 2.32, 2.80, 2.58 and 2.75 ppm/$m\ell$, respectively. Vit. E and Vit. E plus Se groups were slightly higher than those of any other groups, but not significantly difference in 외 I experimental groups(P＜0.05). These results indicate that Se and Vit. E concentrations of blood were slightly increased with the injection of Se and Vit. E in Hanwoo sires.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.3
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• pp.315-322
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• 1998

The objective of this study was to test the effect of catalase on penetration in vitro by spermatozoa preincubated with xanthine and/or xanthine oxidase. The penetration rates were, significantly (p<0.05) higher in spermatozoa preincubated without (66 and 38%) than with (40 and 15%) catalase for 0 and 30 min. When spermatozoa were preincubated and inseminated in medium with xanthine, the penetration rates were significantly higher (p<0.05) in medium with (68, 70 and 49% for 0, 30 and 60 min) than without (33, 41 and 19% for 0, 30 and 60 min) catalase. However, in oocytes were' inseminated with spermatozoa pre incubated with or without catalase in the presence of xanthine oxidase, no decrease in penetrations rates were observed for up to 60 min of preincubation. In another experiment, the penetration rates were significantly (p<0.00l) higher in medium with (75, 55 and 52%) than without (14, 4 and 8%) catalase when oocytes were inseminated with spermatozoa preincubated for 0, 30 and 60 min in the presence of xanthine plus xanthine oxidase. On the other hand, The rate of polyspermy in oocytes penetrated in medium without catalase in the presence of xanthine or xanthine plus xanthine oxidase decreased with time of spermatozoa preincubation. However, no differences were observed in polyspermy rates in the medium with xanthine oxidase alone despite presence of catalase. These results indicate the advantages of spermatozoa pre incubated with xanthine plus xanthine oxidase in the presence of catalase to increase penetration potential and with suppressed polyspermy in porcine.

• Korean Journal of Construction Engineering and Management
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• v.14 no.1
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• pp.32-42
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• 2013

The Korean Government introduced a cultural heritage supervision system in January 2010 to control quality and to prevent poor construction. However, cultural heritage related constructions that require supervision, a scope of supervision, supervision cost and placement of supervisors have not been standardized yet. For this reason, standards of supervision for repair works of cultural heritage that reflect the characteristics of small-scale repair works and restoration of cultural heritage are required. Accordingly, this study has suggested standards of supervision works and cost by analyzing the average construction period that is suitable for the characteristics of cultural heritage repair works. In other words, this study has suggested standards of full-time supervision costs by applying the fixed amount-added method (adding direct labor cost, direct expenses, overhead expenses, engineering fee, charges for additional works and VAT) which is the same as the method of calculating supervision costs for public construction projects because a supervisor has to work full time at a construction site to perform supervision if the project is a mid/large-scale cultural heritage repair work. Also, this study has suggested standards of part-time supervision costs for a small-scale cultural heritage repair work and the ways of supervising the construction projects by visiting the project site on important occasions. According to the result of the analysis by applying the forgoing standards of supervision costs for cultural heritage, a full-time supervision cost for cultural heritage repair works is approximately 98% compared to the construction supervision of a public construction project, and a part-time supervision is approximately 158% compared to architectural construction supervision. It is expected that the valuable cultural heritage of Korea will be preserved by controlling quality of cultural heritage repair works through the application of this study result - the standards of supervision costs for cultural heritage repair works - to an actual project.

• Korean Journal of Agricultural Science
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• v.31 no.1
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• pp.53-75
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• 2004

This study is aimed at identifying the national economic value of the irrigation facilities by reviewing the existing papers on economic values of the irrigation facilities and presenting current status of dual O & M problems of the irrigation facilities. This study suggested the unified O & M system rather than continuing the existing dual O & M system of irrigation facilities based on the surveyed results of the activities of irrigation fraternities in Chungnam Province. The findings and proposals for the successful unified and mono O & M system of the irrigation facilities are as follows: (1) Total number of irrigation facilities in the nation accounts for 67,582, while the total length of irrigation and drainage canals amounted to about 174,259km. On account of the total length of structural canals was estimated at 31%, much losses of water and much O & M costs have been inevitable for the full irrigation rice culture. In spite of the past heavy investment for irrigation facilities, the ratio of rain-fed and partially irrigated paddy fields accounts for 23% in 2003. Both Korea Agricultural and Rural Infrastructure Corporation (KARICO) and the city and Gun Governments have managed the irrigation facilities separately by irrigation fraternities. The KARICO have commanded 59% of irrigation paddy area with 18% of the total irrigation facilities, while the city and Gun governments covered 41% of irrigation paddy area with 82% of the existing number of irrigation facilities representing small and medium scale. (2) The 1999 demand prices of irrigation water per ton expressed in 2000 constant market price was estimated at 388 won, the supply price was amounted to 184 won per ton. Considering the supply and demand curve of the irrigation water, the existing irrigation facilities could not satisfy the demand of irrigation water. (3) In 1999, total present added value of the irrigation facilities during the economic life accounted for 48 trillion won, while total supply cost was 44.7 trillion won. The marginal benefit and cost ratio of irrigation water was 1.08. (4) The total O & M cost per year amounting to 681.1 billion won have been required to maintain and repair the existing irrigation facilities in Korea. For the successful unified O & M of irrigation facilities covering whole irrigated paddy field in Korea, 950 billion won of O & M costs are required to keep up the marginal benefit of irrigation water as 2,800 billion won per year. The total O & M cost as 950 billion won should be allocated 40%, 380 billion won for O & M costs of irrigation facilities and 60%, 570 billion won for improvement of irrigation facilities. (5) The study investigated and reviewed the present O & M status of the irrigation facilities by small and medium irrigation fraternities. Most of the farmers belong to the irrigation fraternities preferred not only unified O & M but also KARICO take-over of the whole O & M activities of the irrigation facilities. The prevailing O & M cost per 10a expended by the Corporation was amounted to 104,890 won, while that of city and Gun governments was only amounted to 4,600 won per 10a. regarding the small amount of O & M cost expended by city and Gun governments, it is evident that the existing irrigation system have been managed ineffectively and deteriorated the facilities comparing that of KARICO. In conclusion, the Government could not satisfied the demand of irrigation water by suppling water with existing irrigation facilities. Therefore new additional investment and financial support for irrigation water development should be made to convert rain-fed and partially irrigated paddy fields into fully irrigated ones. The operation and maintenance cost should be supported to keep the marginal values of rice production of existing irrigation facilities in the national economy and to modernize the obsolete irrigation facilities. By unifying the existing dual O & M systems, all the farmers belong to the irrigated paddy fields have to be equally benefited and could be increased their farm income and be stabilized their rural lives.