• Journal of the Korean Data and Information Science Society
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• v.27 no.4
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• pp.959-967
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• 2016

Distributional assumptions on equity returns play a key role in valuation theories for derivative securities. Elberlein and Keller (1995) investigated the distributional form of compound returns and found that some of standard assumptions can not be justified. Instead, Generalized Hyperbolic (GH) distribution fit the empirical returns with high accuracy. Hu and Kercheval (2007) also show that the normal distribution leads to VaR (Value at Risk) estimate that significantly underestimate the realized empirical values, while the GH distributions do not. We consider saddlepoint approximations to estimate the VaR and the ES (Expected Shortfall) which frequently encountered in finance and insurance as measures of risk management. We supposed GH distributions instead of normal ones, as underlying distribution of linear portfolios. Simulation results show the saddlepoint approximations are very accurate than normal ones.

• International Journal of Reliability and Applications
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• v.15 no.2
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• pp.85-98
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• 2014

Accelerated life testing (ALT) is a well famous technique in life testing and reliability studies, this is particularly used to induce so high stress leading to failure of the highly reliable units quickly under stipulated duration of time. The step-stress ALT is one of the systematic experimental strategy of ALT applied to fail the units in steps. In this article we focus on two important issues (i) necessity of life tests at higher steps with relevant causes (ii) to develop a new optimum test plan for 3-step SSALT under the modified cumulative exposure model proposed by Khamis and Higgins (1998). It is assumed that the lifetime of test units follows Rayleigh distribution and its scale parameter at constant stress level is assumed to be a log-linear function of the stress. The maximum likelihood estimates of the parameters involved in the step-stress ALT model are obtained. A simulation study is performed for numerical investigation of the proposed new optimum plan 3-step, step-stress ALT. The necessity of the life test units at 3-step step-stress is also numerically examined in comparison to simple step-stress setup.

• Journal of the Korean Operations Research and Management Science Society
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• v.17 no.3
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• pp.27-46
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• 1992

This paper considers an (r, Q) policy for operation of a multipurpose facility. It is assumed that whenever the inventory level falls below r, the model starts to produce the fixed amount of Q. The facility can be utilized for extra production during idle periods, that is, when the inventory level is still greater than r right after a main production operation is terminated or an extra production operation is finished. But, whenever the facility is in operation for an extra production, the operation can not be terminated for the main production even though the inventory level falls below r. In the model, the demand for the product is assumed to arrive according to a compound Poisson process and the processing time required to produce a product is assumed to follow an arbitary distribution. Similarly, the orders for the extra production is assumed to accur in a Poisson process are the extra production processing time is assumed to follow an arbitrary distribution. It is further assumed that unsatisfied demands are backordered and the expected comulative amount of demands is less than that of production during each production period. Under a cost structure which includes a setup/ production cost, a linear holding cost, a linear backorder cost, a linear extra production lost sale cost, and a linear extra production profit, an expression for the expected cost per unit time for a given (r, Q) policy is obtained, and using a convex property of the cost function, a procedure to find the optimal (r, Q) policy is presented.

• Preventive Nutrition and Food Science
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• v.2 no.1
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• pp.42-48
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• 1997

the exocrine pancreatic secretion is an important factor in the maintenance of zinc homeostasis. The daily pancreatic secretion of zinc into the gastrointestinal tract may be two or more times the daily dietary zinc intake. The objective of this study was to examine the distribution of proteins and zinc in pancreatic/biliary fluid following intraperitoneal {TEX}${65}^Zn${/TEX} injection into dietary prepared Sprague-Dawly rats. Distribution of zinc-binding protein in Sephadex G-75 subfractions showed a peak corresponding to the high molecular weight protein standard(<66kDa) in the pancreatic/biliary fluid. Zinc also was associated with the 29~35kDa mole-cular weight proteins. These are similar in size with zinc-containing enzymes, carboxypeptidase A and car-boxypeptidase B. A more remarkable small molecular weight fraction eluted beyond the 6.5kDa standard pro-tein peak. These results show the presence of small molecular weight compound in pancreatic/biliary fluid associated with zinc . These small molecular weight compounds may serve as zinc-binding ligands for the secretion of enogenous zinc into the duodenum. These findings suggest that these lignads may dissociate zinc in the duodenum thus making it vulnerable to complexation with phytate in the upper gastrointestinal tract rendering the zinc unavailable for reabsorption.

• Journal of Breast Disease
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• v.6 no.2
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• pp.39-45
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• 2018

Purpose: Dieckol, a phlorotannin compound isolated from Ecklonia cava, has been reported to have antioxidant, antiviral, anti-inflammatory, and anticancer properties. The purpose of this study was to investigate its anticancer effects on human breast cancer cell lines. Methods: In this study, the viability of two human breast cancer cell lines SK-BR-3 and MCF-7 was investigated after dieckol treatment using a WST-1 assay. Apoptosis and cell cycle distribution were assayed via Annexin V-fluorescein isothiocyanate and propidium iodide staining followed by flow cytometric analysis. Immunoblotting analysis was also performed using Bax/Bcl-2 to determine whether the dieckol-induced apoptosis was mediated by the intrinsic apoptotic pathway. Results: In a dose dependent manner, dieckol reduced the number of viable cells and increased the number of apoptotic cells. The effect of dieckol on the cell cycle distribution was analyzed using flow cytometry. Dieckol treatment significantly increased the percentage of MCF-7 and SK-BR-3 in the G2/M phase. Immunoblot analysis revealed that 24 hours of dieckol exposure increased the Bax/Bcl-2 ratio. Conclusion: Dieckol induced cytotoxicity in MCF-7 and SK-BR-3 human breast cancer cells inducing apoptosis and cell cycle arrest. Therefore, it is suggested that dieckol may be a potential therapeutic agent for breast cancer.

• The Journal of Industrial Distribution & Business
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• v.12 no.8
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• pp.41-52
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• 2021

Purpose: The study aims to analyze effects of wage on FDI inflows based on the threshold of institutional quality in 14 developing economies of Southeast and South Asia over the period from 2000-2017. Research design, data, and methodology: The study applies a fixed effect panel threshold regression. As a proxy for the institutional quality, it uses the six components of Worldwide Governance Indicators or a compound index obtained by an average of the six components. The data were taken from World Bank, the Chinn & Ito Database, and UNCTAD. To the best of our knowledge, no researches so far have considered the threshold of institutional quality in estimating the effect of wage on FDI inflows. Results: The composite index and each component of the six indicators of institutional quality except for voice and accountability, and regulatory quality are found to have nonlinear effects on FDI inflows. When the institutional quality is below the threshold, wage affects FDI inflows negatively. When the institutional quality is above the threshold, however, wage does not significantly affect FDI inflows. Conclusions: The effect of wage on FDI inflows varies depending on whether the institutional quality of the target countries is above or below the threshold.

• Journal of environmental and Sanitary engineering
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• v.24 no.4
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• pp.1-26
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• 2009

We conclude the following with air pollution data measured from city measurement net administered and managed in Gwangju for the last 7 years from January in 2001 to December in 2007. In addition, some major statistics governed by Gwangju city and data administered by Gwangju as national official statistics obtained by estimating the amount of national air pollutant emission from National Institute of Environmental Research were used. The results are as follows ; 1. The distribution by main managements of air emission factory is the following ; Gwangju City Hall(67.8%) > Gwangsan District Office(13.6%) > Buk District Office(9.8%) > Seo District Office(5.5%) > Nam District Office(3.0%) > Dong District Office(0.3%) and the distribution by districts of air emission factory ; Buk District(32.8%) > Gwangsan District(22.4%) > Seo District(21.8%) > Nam District(14.9%) > Dong District(8.1%). That by types(Year 2004~2007 average) is also following ; Type 5(45.2%) > Type 4(40.7%) > Type 3(8.6%) > Type 2(3.2%) > Type 1(2.2%) and the most of them are small size of factory, Type 4 and 5. 2. The distribution by districts of the number of car registrations is the following ; Buk District(32.8%) > Gwangsan District(22.4%) > Seo District(21.8%) > Nam District(14.9%) > Dong District(8.1%) and the distribution by use of car fuel in 2001 ; Gasoline(56.3%) > Diesel(30.3%) > LPG(13.4%) > etc.(0.2%). In 2007, there was no ranking change ; Gasoline(47.8%) > Diesel(35.6%) > LPG(16.2%) >etc.(0.4%). The number of gasoline cars increased slightly, but that of diesel and LPG cars increased remarkably. 3. The distribution by items of the amount of air pollutant emission in Gwangju is the following; CO(36.7%) > NOx(32.7%) > VOC(26.7%) > SOx(2.3%) > PM-10(1.5%). The amount of CO and NOx, which are generally generated from cars, is very large percentage among them. 4. The distribution by mean of air pollutant emission(SOx, NOx, CO, VOC, PM-10) of each county for 5 years(2001~2005) is the following ; Buk District(31.0%) > Gwangsan District(28.2%) > Seo District(20.4%) > Nam District(12.5%) > Dong District(7.9%). The amount of air pollutant emission in Buk District, which has the most population, car registrations, and air pollutant emission businesses, was the highest. On the other hand, that of air pollutant emission in Dong District, which has the least population, car registrations, and air pollutant emission businesses, was the least. 5. The average rates of SOx for 5 years(2001~2005) in Gwangju is the following ; Non industrial combustion(59.5%) > Combustion in manufacturing industry(20.4%) > Road transportation(11.4%) > Non-road transportation(3.8%) > Waste disposal(3.7%) > Production process(1.1%). And the distribution of average amount of SOx emission of each county is shown as Gwangsan District(33.3%) > Buk District(28.0%) > Seo District(19.3%) > Nam District(10.2%) > Dong District(9.1%). 6. The distribution of the amount of NOx emission in Gwangju is shown as Road transportation(59.1%) > Non-road transportation(18.9%) > Non industrial combustion(13.3%) > Combustion in manufacturing industry(6.9%) > Waste disposal(1.6%) > Production process(0.1%). And the distribution of the amount of NOx emission from each county is the following ; Buk District(30.7%) > Gwangsan District(28.8%) > Seo District(20.5%) > Nam District(12.2%) > Dong District(7.8%). 7. The distribution of the amount of carbon monoxide emission in Gwangju is shown as Road transportation(82.0%) > Non industrial combustion(10.6%) > Non-road transportation(5.4%) > Combustion in manufacturing industry(1.7%) > Waste disposal(0.3%). And the distribution of the amount of carbon monoxide emission from each county is the following ; Buk District(33.0%) > Seo District(22.3%) > Gwangsan District(21.3%) > Nam District(14.3%) > Dong District(9.1%). 8. The distribution of the amount of Volatile Organic Compound emission in Gwangju is shown as Solvent utilization(69.5%) > Road transportation(19.8%) > Energy storage & transport(4.4%) > Non-road transportation(2.8%) > Waste disposal(2.4%) > Non industrial combustion(0.5%) > Production process(0.4%) > Combustion in manufacturing industry(0.3%). And the distribution of the amount of Volatile Organic Compound emission from each county is the following ; Gwangsan District(36.8%) > Buk District(28.7%) > Seo District(17.8%) > Nam District(10.4%) > Dong District(6.3%). 9. The distribution of the amount of minute dust emission in Gwangju is shown as Road transportation(76.7%) > Non-road transportation(16.3%) > Non industrial combustion(6.1%) > Combustion in manufacturing industry(0.7%) > Waste disposal(0.2%) > Production process(0.1%). And the distribution of the amount of minute dust emission from each county is the following ; Buk District(32.8%) > Gwangsan District(26.0%) > Seo District(19.5%) > Nam District(13.2%) > Dong District(8.5%). 10. According to the major source of emission of each items, that of oxides of sulfur is Non industrial combustion, heating of residence, business and agriculture and stockbreeding. And that of NOx, carbon monoxide, minute dust is Road transportation, emission of cars and two-wheeled vehicles. Also, that of VOC is Solvent utilization emission facilities due to Solvent utilization. 11. The concentration of sulfurous acid gas has been 0.004ppm since 2001 and there has not been no concentration change year by year. It is considered that the use of sulfurous acid gas is now reaching to the stabilization stage. This is found by the facts that the use of fuel is steadily changing from solid or liquid fuel to low sulfur liquid fuel containing very little amount of sulfur element or gas, so that nearly no change in concentration has been shown regularly. 12. Concerning changes of the concentration of throughout time, the concentration of NO has been shown relatively higher than that of $NO_2$ between 6AM~1PM and the concentration of $NO_2$ higher during the other time. The concentration of NOx(NO, $NO_2$) has been relatively high during weekday evenings. This result shows that there is correlation between the concentration of NOx and car traffics as we can see the Road transportation which accounts for 59.1% among the amount of NOx emission. 13. 49.1~61.2% of PM-10 shows PM-2.5 concerning the relationship between PM-10 and PM-2.5 and PM-2.5 among dust accounts for 45.4%~44.5% of PM-10 during March and April which is the lowest rates. This proves that particles of yellow sand that are bigger than the size $2.5\;{\mu}m$ are sent more than those that are smaller from China. This result shows that particles smaller than $2.5\;{\mu}m$ among dust exist much during July~August and December~January and 76.7% of minute dust is proved to be road transportation in Gwangju.

• International Area Studies Review
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• v.21 no.2
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• pp.121-141
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• 2017

The world whitening cosmetics market is fast being taken in 'complex functional cosmetics' including complex function. And highly functional cosmetics market that call cosmeceutical market is growing up with highly functional cosmetics market. In addition, natural cosmetics market including whitening function is growing up in the world in complex functional cosmetics. Distribution channel of the world functional cosmetics is digital communication through beauty and digital. Global companies are adding relationship in new space between customer and brand. So worldwide change phenomenon of whitening cosmetics distribution channel will suggest importance that it should be able to communication with customer in non-traditional space. Domestic whitening cosmetics market is decreasing to reference compound annual growth rate -3.61%. While complex type market is increasing to annual growth rate 33.28%. Since 2008, domestic whitening cosmetics market was changed in distribution channel of center of traditional door-to-door sales. Especially, online channel is about 1/6 level of offline, but since 2014, year-on-year increase rate of online showed 27.1%. In the future, it is anticipated that ratio of online sales is above offline. Whitening cosmetics distribution is being changed, and online channel is growing up, so domestic companies will need tragedy targeting new whitening cosmetics distribution channel and traditional offline channel at the same time. If new company go into whitening cosmetics market, the new company will have to consider natural cosmetics in complex functional cosmetics than whitening cosmetics market. To secure domestic competitiveness whitening cosmetics market, securing differentiation of brand or pursuing change of distribution channel, and we need to seek a method that company and customer can forge communication in new space.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1670-1672
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• 2004

XLPE compound have used for insulation of 22.9kV power cable. XLPE insulation is aged for use long time in distribution line. The cause of aging is water tree is happening and growth. Accelerated water tree test method are Accelerated volatge aging method and high frequency aging method. In this paper, high frequency accelerated water tree was performed. And the result was analysed AC breakdown voltage and size and number of water trees.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.521-528
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• 2003

In this study, a newly modified soil nailing technology called as the NDB(New Down and Board) soil nailing system is introduced. To improve the trafficability, workability, and economical efficiency, SMC(Sheet Molding Compound) board is adopted instead of using the concrete block facing. The SMC board has a distinct advantage of showing a fine view by directly coating with any kind of environmental photos. Composite material properties of the SMC board and cement grout are distinguished features of the NDB soil nailing system. In the present study, both laboratory tests(bending and punching failure tests) and field pull-out tests are carried out to analyze the behavior characteristics of the NDB soil nailing system, including the stress and strain distribution.