• Journal of the Korea Institute of Building Construction
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• v.13 no.4
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• pp.360-371
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• 2013

Fast delivery of construction projects provides more value to project owners. Batch production, which is production not in single pieces, but in batches, is a common approach in repetitive construction projects such as multi-unit residential building construction projects. In batch production, the use of a small batch size allows the early start of subsequent activities, and thus can lead to early completion of projects. In addition to batch size, balance between productivities in construction activities can affect project duration. However, the impact of the balance between productivities with regard to their order on project duration has not been studied. The main goal of this study is to test a hypothesis, which is that the order of construction activities' unbalanced productivities affects the amount of time reduction that can be achieved by using a small batch size. A computer-based simulation model was developed, and five different cases were simulated to test the hypothesis. The conclusion of the simulation result is that the order of productivities does not affect the time reduction achieved by using a small batch size. It is expected that the findings of this study can help general contractors make decisions in terms of batch size.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.3
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• pp.407-415
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• 2018

This study analyzed the role of dams for the flood control by the observed and simulated hourly flood discharge data. The study area was the Nakdong river basin with Andong and Imha dams. For the analysis 31 flood events from 1997 to 2010 were selected. In the analysis of the flood reduction rate (FRR) of dam itself, the FRR was not decreased with higher size of floods which is not as we expected. In order to see the trend of flood reduction rate depending on the flood size, flood discharge volume presents it better than peak flood discharge. In the comparison of the flood reduction effects of the two dams, Andong dam has 7% larger flood reduction influence at the Sungju gauging station (SGS) located farthest from the selected watershed. Comparing the ratio of the watershed area based on the covered size of the SGS, the FRR of dam is smaller than the area rate. The impact of FRR of dam showed that the FRR fell below 10% when reaching the size of watershed area corresponding to 8.5 times of the size of watershed area of the dam which is larger than Namhan river basin (7 times).

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.1
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• pp.1-6
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• 2002

Eggs obtained from 46 and 42 weeks old meat (Hybro) and layer (Leghorn) breeders flocks, respectively were used to examine the effects of genetic type of birds and egg size (small, medium and large) on variables of eggshell characteristics and hatchability traits. The variables measured were egg weight (EW), egg surface area (ESA) and eggshell characteristics (shell conductance (EC), per cent shell (PS), shell thickness (ST), shell volume (SV), shell density (SD) and hatchability traits (per cent hatchability (HP), early dead embryos (ED), late dead embryos (LD), pips with live embryos (PL) and pips with dead embryos (PD)). Genetic type of bird influenced all egg characteristics and HP of eggs. Eggs produced by the small Leghorn bird had lower EW, ESA, EC, ST, SV and HP than those produced by the heavy Hybro bird. The reduction of HP was associated with an increase in the percentage of ED and PL. Egg size influenced all variables measured except ST. Small size eggs had lower EW, ESA and EC and higher PS and SD than those of large eggs. Medium size eggs produced a higher HP when compared with that of large size eggs. The reduction of HP in large eggs was associated with higher percentage of ED, LD and PL. There were significant interactions between the genetic group of birds and egg size on LD and HP. Large egg size of Hybro birds had higher LD and lower HP than those of small size eggs produced by the same flock. However, There was no difference in HP and LD among the different egg sizes produced by Leghorn birds. It was concluded that genetic make up of birds and egg size influence eggshell characteristics and HP. The type of bird (heavy or small) influences the optimum egg size for successful hatching. Attention should be given to the size and eggshell characteristics of eggs of breeders' flocks for achieving maximum HP.

• Archives of Plastic Surgery
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• v.45 no.6
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• pp.517-524
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• 2018

Background Infantile hemangioma (IH) is a common vascular tumor in pediatric patients, and is commonly treated with propranolol. We describe our experiences with dosage, response to treatment, and side effects in 23 IH patients treated with propranolol. Methods For this nonrandomized comparative cohort study, the authors enrolled 23 patients treated with propranolol. Photographs were taken before propranolol administration and at 3, 6, 9, and 12 months after treatment. Treatment responses were objectively analyzed with a computer program. Results There were three male and 20 female patients. Common tumor locations were the head and neck (13 cases, 56.5%), trunk (four cases, 17.4%), extremities (three cases, 13.0%), and combined locations (three cases, 13.0%). The response to propranolol was significantly lower in patients with two or more lesions than in patients with a single lesion in terms of both color fading (P<0.001) and size reduction (P<0.001). In male patients ($42.2{\pm}3.9$), the change in a-values, indicating coloration, was higher than in female patients ($19.8{\pm}13.8$) (P<0.001). In patients who started treatment before 6 months after birth, the size reduction was greater than in their counterparts (62.3%; range, 3.0%-93.0% vs. 15.8%; range, 1.0%-79.0%; P<0.001). Conclusions Propranolol is an efficacious treatment with a good safety profile. In patients with a single lesion, the response to treatment was better in terms of color fading and size reduction. Furthermore, male patients responded better to propranolol treatment in terms of color fading than female patients, and starting treatment before 6 months after birth was more advantageous for size reduction.

• Journal of Korean Neurosurgical Society
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• v.37 no.4
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• pp.275-281
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• 2005

Objective: The prolactinoma is the most common pituitary tumor and sometimes shows severe invasiveness to the adjacent cavernous sinus, especially in the male patient. The dopamine agonist can be used as an alternative treatment modality to surgery. But, the transsphenoidal or transcranial approach for tumor removal has been more preferred treatment option of neurosurgeons in invasive prolactinoma. Especially rapid decompression of mass effect and resolution of the neurologic deficit is demanded. The prospective study is done in order to identify the therapeutic efficacy of bromocriptine as an initial treatment option for the invasive prolactionomas. Methods: Twenty patients with invasive prolactinoma were studied. Preoperative neurological and endocrinological evaluations were done, and size and invasiveness of the tumor was estimated on MRI. Bromocriptine was administrated by increasing dose planning reaching maximum dose at 1 month of treatment, with close neurological and endocrinological monitoring. At 3months after treatment, MRI was taken and decision was made whether to continue bromocriptine or to have surgical intervention. Results: Thirteen patients showed excellent result with only bromocriptine treatment. These patients showed not only marked reduction of tumor volume and prolactin level, but also, improving clinical symptoms and other hormonal deficits. 13patients who had visual field defect and decreased visual acuity had all improved visual symptoms. But, the remaining 4patients required surgical treatment due to insufficient reduction of tumor size inspite of normalized prolactin level within 3months. Remaining 2patients had $20{\sim}30%$ of tumor size reduction, but prolactin level was not normalized. One patient required radiation therapy. Conclusion: Bromociptine can be used as initial treatment for the invasive prolactinomas with careful monitoring of the neurological and endocrinological status. It should be carefully followed up for tumor size reduction within 3 months after initiation of treatment.

• Journal of Labour Economics
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• v.37 no.1
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• pp.1-28
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• 2014

We use a set of Korea panel data to estimate effects of legal working hours reduction on actual hours worked and employment effects, through panel econometrics methods. Taking account of sequential decrease in legal hours worked since 2004, we estimate the relationship between legal and actual working hours by size of industries. It is found that one hour reduction of legal hours per week caused 0.44 to 1.05 actual hours worked on average per week, depending on different industrial sizes. Also, estimated employment effects were not unanimously determined, rather they turn out to be clearly size-dependent, which provide different results from exiting literature. Our analysis proposed in this work can be restrictive as, for instance, there is significant lack of data for foreign workers, particularly in the small-sized industries. Subsequent empirical analysis is expected.

• Journal of Nutrition and Health
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• v.30 no.2
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• pp.123-131
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• 1997

The influence of (-0-Hydroxycitrate(HCA), shown to be a competitive inhibitor of adenosine 5-triphosphate(ATP) citrate lyase, on food intake and body weight, serum triglyceride and cholosterol level, in vivo rates of fatty acid and cholesterol synthesis, and fat cell number and size was investigated. 3 groups of female, 5 weeks old Sprague Dawley rats, 8 animals each, were ad libitum meal-fed or pair-fed(3 hours from 10 : 00 to 13 : 00) AIN based high glucose diet for a total period of 8 weeks. Providing normolipidemic rats orally with 400mg of HCA formula containing approximately 20mg of HCA 1 hour prior to daily feeding schedule significantly depressed in vivo hepatic rates of fatty acid and cholesterol synthesis in the liver and adipose tissue. Serum triglyceride and cholesterol levels were significantly reduced by HCA. At the end of treatment period, the rats administered with HCA resulted in a significantly reduction in body weight gain. The reduction in weights was attributable to a significant decrease in fat cell size with a smaller extent, but not significant, reduction in fat cell number. Rats receiving HCA demonstrated less food intake than the controls ; however, this decreased caloric intake was not fully responsible for the HCA induced depression of hepatic and adipocytic lipogenesis, since experiment using pair-fed cojntrol rats showed, less magnitude but similar results. Both a anorectic and an antilipogenic properties of HCA seem to be responsible for this weight reduction activity of HCA. The outcome of this study suggest that metabolic regulation may be a feasible approach to the control of obesity and hyperlipidemia.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.398-403
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• 2001

There is a potential usability of electric arc furnace(EAF) dust produced during the iron manufacturing process as a recycled resource, because valuable materials such as Zn, Pb and Fe are contained in it. In this study, metallic Zn was recycled from the fine electric arc furnace dust by a solid state reduction method using carbon at relatively low temperature. It was possible to recover metallic zinc by using of high vapour pressure of zinc with this reduction method. The feasibility of recycled zinc for cold bonded pellet(CBP) was investigated. The main composition of EAF dust were franklinite(ZnFe$_2$O$_4$), magnetite(Fe$_3$O$_4$) and zincite(ZnO), and Pb and Cl were completely removed by a heat treatment in oxidation environment. The reduction ratio increased as the solid carbon content increased, and it increased with decreasing of dust particle size and increasing of compaction pressure due to a increase of contact area.

• Korean Journal of Materials Research
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• v.13 no.8
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• pp.524-530
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• 2003

In order to prepare the uniform copper particles from copper sulfate solution by using hydrazine as a reduction agents, the reduction behavior of copper particles from copper sulfate was investigated in detail at room temperature by the observation of reaction products. The effects of $NH_4$OH and $Na_4$$P_2$$O_{7}$ on the formation of uniform copper particles were discussed. ($NHCu_3$)$_4$$SO_4$was completely formed at over pH 11 by adding $NH_4$OH in copper sulfate solution. The fine $Cu_2$O with the particle size of 50 nm was produced in the initial reduction process of (NH$Cu_3$)$_4$$SO_4$solution with $Na_4$$P_2$$O_{ 7}$ and then the Cu$_2$O was converted into copper particles by inserting additional hydrazine. When Cu(NH$_3$)$_4$SO$_4$solution with $Na_4$$P_2$$O_{ 7}$ was reduced at $80^{\circ}C$ by hydrazine, the highly dispersed copper particles with the particle size of about 0.8 $\mu\textrm{m}$ was obtained.

• The Journal of Korean Society for Radiation Therapy
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• v.8 no.1
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• pp.41-54
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• 1996

The secondary electrons developed by interaction between primary beam and a tray mounted for blocks in Megavoltage irradiation result in excess soft radiation dose to the surface layer. To reduce this electron contamination, electron filters have been used to be attached under a tray. Various filters with Cu and Al plates in six different thickness and Cu/Al combined plates in 3 different thickness were tested to measure the reduction rate of secondary electron contamination to the surface layer. The measurement to find optimal filter was performed on 6MV linear accelerator in $10 cm{\times}10 cm$ field size and fixed 78.5cm source to measurement points distance from surface to maximum build up point in 2mm intervals. The result was analyzed as the ratio of measured doses with using filters, to standard doses of measured open beam. The result of this study was fellowing : 1. The contaminated low energy radiation were mainly produced by blocking tray. 2. The surface absorbed dose was slowly increased by increasing irradiation field size but rapidly increased at field size above $15cm{\times}15cm$. 3. Al plate upto 2.5mm thickness used as a filter was found to be inadequate due to the failure of reduction of the surface absorbed dose below doses of the under surface upto the maximal build up. Cu 0.5mm plate and Cu 0.28mm/A1 1.5mm compound plate were found to be optimal filters. 4. By using these 2 filters, the absorbed dose to the surface were effectively reduced $5.5\%$ in field size $4cm{\times}4cm,\;11.3\%$ in field size $10cm{\times}10cm,\;22.3\%$ in field size $25cm{\times}25cm$. 5. In field size $10cm{\times}10cm$, the absorbed dose to the surface of irradiation was reduced by setting TSD 20cm at least,. but effective and enough dose reduction could be achieved by setting TSD 30cm as 2 optimal filters used. 6. More surface dose absorbed at TSD less than 7.4cm with a tray and filters together indicated that soft radiation was also developed by filters. 7. The variation of PDD by the different size of irradiation field was minimal as 2 optimal filters used. There was also not different in variation of PDD according to using any of two different filters. 8. PDD was not effected either by various TSD or by using the different filter among two.