• Journal of Power System Engineering
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• v.8 no.3
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• pp.44-51
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• 2004

Effect of corrosion characteristics in relation to loaded stress in the welded zone of A5083-H116 aluminum alloy, in the seawater was studied. The corrosion experiment was performed for 120 hours on the specimens in the natural seawater tank with four steps of the loaded stress. The corrosion crack, corrosion rate, electrode potential, current, and corrosion pattern, etc. were examined for the specimens with the elapse of the immersion time. The main result derived from this study is the crack growth length is increased with the increasing loaded stress. The electrode potential and the corrosion current are decreased rapidly in the early stage of the corrosion, and then decreased gradually and stabilized eventually with the elapse of the immersion time. The test condition of the longer crack growth tends to show the higher corrosion rate. Corrosion pattern of the welded zone indicates that the depth and width of the pitting become increasing with the increasing loaded stress.

• Korean Journal of Animal Reproduction
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• v.7 no.1
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• pp.41-51
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• 1983

The purpose of this experiment was to investigate the effects of adrenalectomy and PMSG treatment on reproductive organs and serum steroid hormone level in immature female rats. The animals used in this experiment were 25 days old female rats weighing a, pp.oximately 70g. They were randomly divided into two groups of intact rat group (Int-) and adrenalectomized rat group (Adx-) and each group were subdivided into two groups of Non-PMSG (-Cont) and PMSG treated (-PMSG) group. The rat of PMSG-treated group (-PMSG) was administered subcutaneously with 25 IU PMSG on first day (9 a.m.) after adrenalectomy. The adrenalectomized rat groups were su, pp.ied with saline solution through the experiment period. The rate of ovulation and vaginal opening and reproductive organ weights were observed at 8, 32, 56, 80 and 104 hours after PMSG treatment. At the same time, the serum level of estradiol-17${\beta}$ and progesterone were measured by the radioimmunoassay. The results obtained were as follows: 1. Ovulation was shown at 56 hours after treatment in Int-PMSG group and Adx-PMSG group and Adx-PMSG group. The rate of ovulation was very low in PMSG-treated groups, but it was increased in 80 to 90% at 104 hours after treatment. However, there was no ovulation in Int-Cont group and Adx-Cont group. 2. Vaginal opening was shown at 56 hours after treatment in Int-PMSG group and Adx-PMSG group and a, pp.ared in 80% at 104 hours after treatment. The rate of vaginal opening in PMSG-treated groups was very low, but Int-Cont group and Adx-Cont group had no vaginal opening. 3. The weight of ovary and uterus in two PMSG-treated groups were increased with the elapse of time after treatment and were significantly heavy in all observation time, but changes in Int-Cont group and Adx-Cont group were not recognized. The weights of ovaries and utera in Adx-Cont group were increased with the elapse of time. 4. The level of serum estradiol-17${\beta}$ was remarkably increased in PMSG-treated groups (Int-PMSG and Adx-PMSG groups) compared with Int-Cont and Adx-Cont group, and significant difference was recognized between Non-PMSG group and PMSG-treated group in the experimental period. Especially, the highest levels of Int-PMSG groups and Adx-PMSG groups were shown at 80 and 56 hours after treatment and after ward estradiol-17${\beta}$ levels of PMSG-treated groups were decreased. However, changes of the levels did not a, pp.ared in Non-PMSG groups at 104 hours after treatment. 5. The level of serum progesterone in PMSG-treated groups was significantly increased between 80 and 104 hours after treatment. With the elapse of time, the level was increased in all observed groups except for Int-Cont and Adx-Conx group. And the order from the highest level at 104 hours after treatment was Int-PMSG, Adx-PMSG, Int-Cont and Adx-Cont group.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.1
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• pp.82-94
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• 1997

For the purpose of establishing the most appropriate method of bonding between glass ionomer liners and composite resin and comparing the materials for sandwich technique, an experiment was performed to measure the shear bond strengths between the two with the variables in the surface treatment of liners and elapsed time till composite buildup. Materials used were Vitrebond and Fuji II LC, each as the restorative and liner respectively, and each group was subdivided by surface treatment (acid etching and sandblasting) and time elapsed from GIC filling to composite buildup (immediately, 1 day, 7 days), consisting 12 groups as a whole. Each subgroup was composed of 10 specimens and the shear bond strength between GIC liners and composite resin was measured under UTM and analyzed. The result were as follows: 1. The shear bond strength between two materials was highest when initially filled Fuji II LC was sandblasted after 1 days and composite built-up (Group FS1). And the lowest value was found when GIC was acid-etched after 7 days and composite built-up (Group FE7). Significant difference was found between the two groups. (P<0.01) 2. In regard of surface treatment of GI liners, acid-etched group (VE) showed higher bond strength than sandblasted group (VS) for Vitrebond. But, the reverse was true for Fuji II LC. (P<0.05) 3. In regard to the time elapsed from GI filling to composite buildup, the group of 1 day elapse showed relatively higher strength for Vitrebond. On the contrary, immediate buildup group (FE0) was stronger for acid-etched group and 1 day elapse group(FS1) was higher for sand-blasted group in Fuji II LC. (P<0.05)

• KIEAE Journal
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• v.11 no.3
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• pp.63-68
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• 2011

Building deterioration would be proceeded by various causes such as physical, social, economic degradation. The deterioration would be inevitably prevented or delayed to get the decent function and performance in various building part and components. The maintenance and management are continued to provide the decent living condition for the household. The maintenance means mainly a repair, including the on-time and longterm plan. The longterm repair would be conducted by the systemic preparation in management activity and a required cost. Therefore, the annual due for the longterm repair plan is important to prepare the repair cost in a required time. In this paper, it aimed at analyzing the longterm repair cost and modelling to forecast the required cost in total area, number of household and time elapse in apartment housing. The estimation model of a repair cost is used with a power function which has a good statistics. Results of this study are shown that the sample has a longterm repair due in a $2,032won/m^2{\cdot}yr$ averagely which is higher than $912won/m^2{\cdot}yr$ in domestic. Second, the longterm repair due is proportionally correlated with the time elapse in both a total area and the number of household. Third, the estimation model for the longterm repair amount is suitable for the power function which is most in any other estimation models. Fourth, the ration of the longterm plan repair due a year to the cumulated longterm amount is about 26%.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.3
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• pp.129-138
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• 2014

This paper is to analyze the cycle time of the vendor in a single-vendor multi-buyers supply chain. The vendor is the manufacturer and the buyers are the retailers. The cycle time of the vendor is the elapse time from the beginning time of the production to the beginning time of the next production. The cycle time of the vendor that minimizes the total cost in a supply chain is analyzed. The cost factors are the production setup cost and the inventory holding cost of the vendor, the ordering cost and the inventory holding cost of the retailers. The cycle times of the vendor obtained with the costs of the vendor is compared with those obtained with the costs of the vendor and the retailers. Various numerical examples are tested if the cycle times of the vendor for both methods are the same.

• Journal of the Korean housing association
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• v.17 no.2
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• pp.19-26
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• 2006

Building would be deteriorated with time elapse, influenced by its geographic situation, climate and other environmental conditions. In addition, the systematic maintenance could be provided to keep the resident a recent living condition. The existing breakdown maintenance will be changed into the preventive maintenance. The preventive maintenance is required to get the repair time, the repair scope and frequency. In this paper, it aimed at providing the repair time range over the building components, utilizing the relation between the determination curve and the performance recovery through repair. Results of this study are as follows : First, the forecast of the repair time over the building components could be calculated and equalized with the deterioration and performance degree. Second, the repair time range of building components would be provided into five categories and 3rd repair time. Results of this study will set up the long-term repair plan of building, and finally keep an housing condition comfortable.

• Geomechanics and Engineering
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• v.16 no.2
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• pp.159-168
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• 2018

In this study, a real-time grouting management system based on the clogging theory was established to manage injection procedure in real time. This system is capable of estimating hydraulic permeability with the passage of time as the grout permeates through the ground, and therefore, capable of estimating real time injection distance and flow rate. By adopting the Controlled Injection Pressure (CoIP) model, it was feasible to predict the grout permeation status with the elapse of time by consecutively updating the hydraulic gradient and flow rate estimated from a clogging-induced alteration of pore volume. Moreover, a method to estimate the volume of the fractured gap according to the reduction in injection pressure was proposed. The validity of the proposed system was successfully established by comparing the estimated values with the measured field data.

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.147-148
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• 2006

Relative phase distribution of onion epidermal cells was measured by using the relative phase microscope with inverse linear polarizing method. Decrease of relative phase distribution of onion epidermal cells was also investigated as the elapse of time. In decrease of relative phase distribution, relative phase of cell membrane in onion epidermal cells decreased radically as compared with that of cytoplasm.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2007.04a
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• pp.30-36
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• 2007

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.1001-1006
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• 2000

These should be constructed partially, because many prestressed concrete box girder bridges in situ have large cross section and long span. Therefore, accurate prediction of differences, both elapse time of each construction stage and exposure of atmosphere at each position of cross section, is very important. Though it is importance, engineers are apt to overlook it. This study predicted cracks due to shrinkage and stress concentration phenomenon by each construction stage and then, ascertained reduction of tensile stresses after applying retrofit scheme.