• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.12
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• pp.1335-1341
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• 2011

The purpose of this research is to investigate how separated and reattached flow affects mass transfer, by comparing the local mass transfer characteristics on an inclined flat plate with those on a parallel flat plate. The local mass transfer coefficients for the flat plate were measured using the naphthalene sublimation technique; the inclined angle of the flat plate was varied from $-10^{\circ}$ to $10^{\circ}$ at $5^{\circ}$ intervals, and the free-stream velocity was varied from 2m/s to 15m/s. At positive inclined angles, the local Sherwood numbers decreased gradually because the boundary-layer thickness increased. On the other hand, for negative inclined angles, the local Sherwood numbers assumed the minimum value at the separation point of the recirculation flow and the maximum value at the reattachment point. The average Sherwood numbers for both positive and negative inclined angles were lower than those in the case of the parallel plate.

• Journal of the Korean Geotechnical Society
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• v.25 no.9
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• pp.5-17
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• 2009

The microcomputer program PileNSF (Pile Negative Skin Friction) is developed by the authors in a graphical user interface (GUI) environment using $MATLAB^{(R)}$ for predicting the bearing capacity of a pile embedded in a consolidating ground by surcharge loading. The proposed method extends the one-dimensional soil-pile model based on the nonlinear load transfer method in OpenSees to perform an advanced one-dimensional consolidation settlement analysis based on finite strain. The developed program has significant features of incorporating Mikasa's finite strain consolidation theory that accounts for reduction in the thickness of the clay layer as well as the change of the soil-pile interface length during the progress of consolidation. In addition, the consolidating situation of the ground by surcharge filling after the time of pile installation can also be considered in the analysis. The program analysis by the presented method has been verified and validated with several case studies of long-term test on single piles subjected to negative skin friction. Predicted results of negative skin friction (downdrag and dragload) as a result of long from consolidation settlement are shown to be in good agreement with measured and observed case data.

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1683-1688
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• 2007

This paper presents a novel simple method for introducing gold nanoparticles in a poly(4-vinylpyridine) (PVP) polymer layer over a glassy carbon (GC) electrode with the aim of forming a tunable electrochemical interface against a cationic ruthenium complex. Initially, AuCl4 ? ions were spontaneously incorporated into a polymer layer containing positively charged pyridine rings in an acidic media by ion exchange. A negative potential was then applied to electrochemically reduce the incorporated AuCl4 ? ions to gold nanoparticles, which was confirmed by the FE-SEM images. The PVP layer with an appropriate thickness over the electrode blocked electron transfer between the electrode and the solution phase for the redox reactions of the cationic Ru(NH3)6 2+ ions. However, the introduction of gold nanoparticles into the polymer layer recovered the electron transfer. In addition, the electron transfer rate between the two phases could be tuned by controlling the number density of gold nanoparticles.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.7
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• pp.655-660
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• 2009

In many real applications, the discrepancy problem between controller outputs and plant inputs or the abrupt variation problem of controller outputs can occur. These problems have a negative effect on control performance and stability. It is well-known that two phenomena called 'windup' and 'bump' cause these problems. So far these problems have been studied separately in each side of the anti-windup and the bumpless transfer. This paper proposes a new unified method combines the anti-windup and the bumpless transfer method using the linear quadratic minimization and a proper state space model representation for the anti-windup controller. The proposed method has a feature that it takes account of both the anti-windup and the bumpless transfer in one formula. Finally, we exemplify the performance of the proposed method via numerical examples using the controller switching between the anti-windup PID controller and the anti-windup LQ controller.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.115-115
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• 2002

To evaluate the correlations between the expression of cyclin B1 mRNA and protein after stimulation and oocyte activation and development of nuclear transferred mouse embryos, this study was performed. The oocyte activation was induced by 7% ethanol or 10$\mu\textrm{g}$/$m\ell$ Ca-ionophore without (single) or with (combined) 10$\mu\textrm{g}$/$m\ell$ cycloheximide (CH). Cyclin B1 mRNA and protein in mouse oocytes was evaluated by PCR and western blot. The activation and blastocyst development in both single (P<0.05) and combined (P<0.01) stimulation was higher than in non-activated group. The cyclin B1 mRNA and protein levels were significantly reduced in both single and combined stimulation groups (P<0.05), respectively. Cyclin B1 mRNA expression showed a negative correlation between activation and blastocyst development in both single and combined stimulation groups. And also the expression of cyclin B1 protein showed a negative correlation with between oocyte activation and blastocysts development in both single and combined stimulation groups. In conclusion, it may suggest that single and combined stimulation increases the oocyte activation and blastocyst development of nuclear transferred embryos, because it induces the degradation of cyclin B1 mRNA and protein after activation in enucleated mouse oocytes.

• The Journal of Information Systems
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• v.27 no.1
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• pp.193-224
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• 2018

Purpose Targeting Korean companies listed on Korean securities markets (i.e., KOSPI and KOSDAQ markets), this study aims to shed lights the effects of personal information security breaches on stock prices of information security companies. Interestingly, this study is, to the best of our knowledge, the first to examine the information transfer effect on personal information security breaches of companies. Design / Methodology /Approach To examine the information transfer effect of personal information security breaches, our study employs the event study commonly used in financial studies. To this end, we investigate a variety of events of personal information security breaches of companies listed on the KOPSI stock market and the KOSDAQ market. We collect the total samples of one hundred and twelve with forty seven of events of personal information security breaches by thirty companies and sixty five of information security companies. Findings The principal findings from the empirical study are as follows. First, for companies of personal information security breaches, our event study presents the significantly negative AAR (averaged abnormal return) value on the event day at the 5 % level and the highly significant negative CAAR(cumulative averaged abnormal return) value on the event day and the day after the event day at the 1 % level. The results suggest that personal information breaches significantly contribute to an decrease in value of the information breached companies. The cross sectional regressions in this study estimate the significantly negative coefficient for the ME/BE variable, the proxy for a growth opportunity at the 5 % level. This suggests a reverse relation between the growth opportunity of companies and their value. As for the various samples of the information security companies categorized by physical security, network and system security, security application software, code authentication, system integration, we find the significantly positive AAR on the day after the event day at the 5% level, only for the network and system security-companies. This addresses that the information transfer effect followed by personal information breaches is uniquely observable for companies categorized into network and system companies. The regressions for the network and system companies estimate the significantly positive coefficient for the NS dummy variable (i.e., the dummy of the network and system security companies) at the standard level. This allows us to identify appropriate times needed to make the information transfer effect realized from personal information breached companies to information security companies.

• Culinary science and hospitality research
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• v.24 no.3
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• pp.133-143
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• 2018

The purposes of this study was to investigate how interpersonal relationship stress had the impact on job attitude and turnover intention. To perform this study, total 420 questionnaire were distributed to regular hotel employees from October 16th to November 26th in 2017. Unworkable data were excluded, and final 344 usable responses were obtained for an empirical analysis. Frequency analysis, exploratory factor analysis, reliability analysis, correlation analysis and regression analysis were measured by using SPSS 18.0, respectively. For the study structure, interpersonal relationship stress primarily concentrated on the boss/staff/colleague/customer stress. Job attitude was divided into organization commitment and job satisfaction. Transfer intention was a single factor. The results of this study were shown as follows: Hypothesis 1, boss/customer stress have a negative effect on organization commitment and boss/colleague/customer stress have a negative effect on job satisfaction. Hypothesis 2, boss/customer stress have a positive effect on transfer intention. Hypothesis 3, tissue commitment have a negative effect on transfer intention. This results of this study have shown that stress management of employee is a source of management result in hotel business. This study have given to the hotel's human resource management and internal marketing for the practical implication and academical use.

• The Journal of Small Business Innovation
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• v.19 no.3
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• pp.43-55
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• 2016

This study examines the implications of special items (SI) for future earnings using quarterly Korean data over the period from 2011 to 2014. Due to the lack of identification of SI in Korea, I choose several items as special items if they are material and non-recurring items following prior studies. Then I regressed seasonally-differenced future earnings on positive and negative SI and found that their effects on future earnings were different. While negative SI are explained by inter-period expense transfer, positive SI are not well-described by traditional prototypes. Next, I regressed seasonally-differenced future earnings on negative SI sub-types as they are heterogeneous in nature and have differing implications for future earnings. While PPE impairments and intangibles impairments are partly explained by the inter-period expense transfer, unspecified loss of other loss items are not. Interestingly, these effects are attenuated or disappear in the Kosdaq market when the markets are divided into the Kospi and Kosdaq markets.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.31 no.4
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• pp.349-356
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• 2007

The present study investigated local heat/mass transfer characteristics on the tip of the rotating turbine blade with various incoming flow incidence angles. The experiments are conducted in a low speed annular cascade with a single stage turbine. The blade has a flat tip with a mean tip clearance of 2.5% of the blade chord. The incoming flow Reynolds number is $1.5{\times}10^5$ at design condition. To examine the effect of off-design condition, the experiments with various incidence angles ranging between $-15^{\circ}$ and $+7{\circ}$ were conducted. A naphthalene sublimation method is used to measure detailed mass transfer coefficient on the blade. The results indicated that the incidence angle strongly affects the behavior of tip leakage flow around the blade tip and consequently plays an important role in determining heat transfer characteristics on the tip. For negative incidence angles, the heat/mass transfer in the upstream region on the tip decreases by up to 20%. On the contrary, for positive incidence angles, much higher heat transfer coefficients are observed even with small increase of incidence angle.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.232-235
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• 1998

Air sparging system is a kind of in-situ bioremediation method in the contaminated ground water. When Air sparging, the both of water circulation and oxygen transfer happend in the same time. The hydraulic differential head is zero at the middle height of well, is negative below the height and is possitive above the height. Hydroraulic head gradient is proportioned to air superficial velocity in the well. But over 24m/min of the superficial velocity, the hydraulic head gradient increase little.