• Bulletin of the Korean Mathematical Society
• /
• v.54 no.6
• /
• pp.2165-2182
• /
• 2017

Let G be a group and $\mathbb{C}$ the field of complex numbers. Suppose ${\sigma}:G{\rightarrow}G$ is an endomorphism satisfying ${{\sigma}}({{\sigma}}(x))=x$ for all x in G. In this paper, we first determine the central solution, f : G or $G{\times}G{\rightarrow}\mathbb{C}$, of the functional equation $f(xy)+f({\sigma}(y)x)=2f(x)+2f(y)$ for all $x,y{\in}G$, which is a variant of the quadratic functional equation. Using the central solution of this functional equation, we determine the general solution of the functional equation f(pr, qs) + f(sp, rq) = 2f(p, q) + 2f(r, s) for all $p,q,r,s{\in}G$, which is a variant of the equation f(pr, qs) + f(ps, qr) = 2f(p, q) + 2f(r, s) studied by Chung, Kannappan, Ng and Sahoo in [3] (see also [16]). Finally, we determine the solutions of this equation on the free groups generated by one element, the cyclic groups of order m, the symmetric groups of order m, and the dihedral groups of order 2m for $m{\geq}2$.

• Journal of Navigation and Port Research
• /
• v.31 no.8
• /
• pp.705-710
• /
• 2007

The productivity of automated container terminals is significantly affected by not only the speed related performances of automated transfer cranes(ATCs) but also the sizes of container blocks. In this paper, it is discussed how to determine the size of import container blocks considering both the container handling times of an ATC and their storage space. Firstly, evaluation models are suggested for the container handling times of an ATC in a typical import container blocks. Secondly, three mathematical formulations are suggested to determine the size of import container blocks. Numerical experiments for the suggested models to determine the size of import container block are provided.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.33
• /
• pp.91-118
• /
• 2007

In the transaction of credits, banks must examine the presentation to determine, on the basis of the documents alone, whether or not the documents appear on their face to constitute a complying presentation. And bank shall each have a maximum of five banking days following the day of presentation to determine if a presentation is complying. This period does not depend on any upcoming expiry date or last day for presentation. Data in a document, when read in context with the credit, the document itself and international standard banking practice, need not be identical to, but must not conflict with, data in i) that document; ii) any other stipulated document; or iii) the credit. When a bank determines that a presentation is complying, it must honour or negotiate. But, when a bank determine that a presentation does not comply, it may refuse to honour or negotiate. When a bank decides to refuse to honour or negotiate, it must give a single notice to that effect to the presenter. That notice must be given by telecommunication or, if that is not possible, by other expeditious means no later than the close of the fifth banking day following the day of presentation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.10
• /
• pp.52-58
• /
• 2009

In this paper, we propose a probability method to determine minimum capacity of energy storage system(ESS) for Micro-grid Because of high capital cost of ESS, It's very important to determine optimal capacity of ESS and for stable operation of Micro grid(MG), we should determine minimum capacity of ESS. The proposed method has abilities to consider forced outage rate of generators and intermittent of non-dispatchable generators and minimum capacity make MG keep energy balancing by oneself.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
• /
• v.15
• /
• pp.119-136
• /
• 2001

The purpose of this paper is to consider how to decide the cause of loss or damage to the transport goods when maritime accident occurs. In marine insurance, the underwriter is liable for any loss or damage proximately caused by a risk insured(MIA Art.55). So it is very important to determine the proximate cause of loss or damage to ascertain whether it is to be recoverable under the policy. But there is no definite conception or rule what is the proximate cause. It was left to the tribunal as a question of fact. In this paper, I will suggest the general rules to determine the proximate cause of loss or damage of the transport goods in marine insurance. First, in MIA 1906, there is the rule of proximate causation and it has been established the effective causation by cases since 1918. Second, in Institute Cargo Clauses(B) & (C), there are rules of considerably relaxed standards to determine the causation of loss of or damage using the "attributable to" and "caused by" basis. Third, it is noted, under the complex causation situation, there are difference basises to decide the liability of underwriters between the case of successive occurrence of single risk and the case of concurrent occurrence of several risks. Forth, in practice, it couldn't be ascertained the underwrier's liability by a definite rule and it should be fully considered the circumstances and conditions of the loss.

• Journal of Korean Society for Atmospheric Environment
• /
• v.9 no.3
• /
• pp.207-215
• /
• 1993

In order to statistically predict $O_3$ levels in Seoul, the study used the TMS (telemeted air monitoring system) data from the Department of Environment, which have monitored at 20 sites in 1989 and 1990. Each data in each site was characterized by 6 major criteria pollutants ($SO_2, TSP, CO, NO_2, THC, and O_3$) and 2 meteorological parameters, such as wind speed and wind direction. To select proper variables and to determine each pollutant's behavior, univariate statistical analyses were extensively studied in the beginning, and then various applied statistical techniques like cluster analysis, regression analysis, and expert system have been intensively examined. For the initial study of high level $O_3$ prediction, the raw data set in each site was separated into 2 group based on 60 ppb $O_3$ level. A hierarchical cluster analysis was applied to classify the group based on 60 ppb $O_3$ into small calsses. Each class in each site has its own pattern. Next, multiple regression for each class was repeatedly applied to determine an $O_3$ prediction submodel and to determine outliers in each class based on a certain level of standardized redisual. Thus, a prediction submodel for each homogeneous class could be obtained. The study was extended to model $O_3$ prediction for both on-time basis and 1-hr after basis. Finally, an expect system was used to build a unified classification rule based on examples of the homogenous classes for all of sites. Thus, a concept of high level $O_3$ prediction model was developed for one of $O_3$ alert systems.

• Structural Engineering and Mechanics
• /
• v.52 no.6
• /
• pp.1085-1098
• /
• 2014

Plastic mechanism analysis of structures subjected to large deformation has long been used in order to determine collapse mechanisms of steel structures, and the energy absorbed in plastic deformation during such collapses. In this paper the technique is applied to vehicle roof structures that undergo large plastic deformation as a result of rollover crashes. The components of such roof structures are typically steel spot-welded hat-type sections. Ten different deformation mechanisms are defined from investigations of real-world rollover crashes, and an analytical technique to determine the plastic collapse load and energy absorption of such mechanisms is determined. The procedure is presented in a generic manner, such that it may be applied to any vehicle structure undergoing a rollover induced collapse. The procedure is applied to an exemplar vehicle, in order to demonstrate its application in determining the energy absorbed in the deformation of the identified collapse mechanisms. The procedure will be useful to forensic crash reconstructionists, in order to accurately determine the initial travel velocity of a vehicle that has undergone a rollover and for which the post-crash vehicle deformation is known. It may also be used to perform analytical studies of the collapse resistance of vehicle roof structures for optimisation purposes, which is also demonstrated with an analysis of the effect of varying the geometric and material properties of the roof structure components of the exemplar vehicle.

• Clinical and Experimental Reproductive Medicine
• /
• v.39 no.2
• /
• pp.73-80
• /
• 2012

Objective: This study was undertaken to determine the effect of hypoxia inducible factor (HIF)-$1{\alpha}$ on the cell death, autophagy, and invasion of trophoblasts. Methods: To understand the effect of HIF-$1{\alpha}$, we inhibited HIF-$1{\alpha}$ using siRNA under normoxia and hypoxia conditions. Invasion assay and zymography were performed to determine changes in the invasion ability of HIF-$1{\alpha}$. Western blotting and immunofluorescence were performed to determine some of the signal events involved in apoptosis and autophagy. Results: There was no difference in cell death through the inhibition of HIF-$1{\alpha}$ expression by siRNA; however, the expression of LC3 and autophagosome formation increased. On the other hand, autophagy was increased, and the invasive ability of trophoblast cells decreased according to the inhibition of HIF-$1{\alpha}$ expression by siRNA. These experimental results mean that HIF-$1{\alpha}$ genes regulate the invasive ability of trophoblasts by increasing autophagy. Conclusion: This study contributes important data for understanding the mechanism of early pregnancy implantation and the invasive ability of trophoblasts by defining the relationship between the roles of HIF-$1{\alpha}$ and autophagy.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.11 no.4
• /
• pp.511-517
• /
• 1999

Determining the simultaneous flow rate in any particular section of piping is the important step in order to determine the size of water supply piping. Now we are using the diversity curve of common water closet in order to determine the simultaneous flow rate of water supply piping, but there is a difference between a determined flow rate of general water closet and that of water closet for water saving. This study aims to find out the fixture unit of a flush valve type water closet for water saving in office building, and to determine the correlation between the fixture units and peak flow rates on the basis of the probability theory. A flush valve type water closet for water saving that have a 7.5 second duration of flush operation with an average design flow rate 72 $\ell$/fin was considered. Simulation results indicate that the number 5 is shown to be reasonable to the fixture unit of water closet for water saving. And the design can be undersized considerably with the revised diversity curves using modified fixture unit.

• Journal of the Earthquake Engineering Society of Korea
• /
• v.18 no.6
• /
• pp.301-308
• /
• 2014

A suspension bridge is a type of bridge in which the beam is suspended by load-bearing cables. There are two classifications: the self-anchored suspension bridge has the main cable anchored to the bridge girders, and the earth-anchored suspension bridge has the main cable anchored to a large anchorage. Although a suspension bridge is structurally safe, it is prone to be damaged by various actions such as hurricanes, tsunamis and terrorist incidents because its cables are exposed. If damage to a cable eventually leads to the cable rupture, the bridge may collapse. To avoid these accidents, studies on the dynamic behavior of cable bridges due to the cable rupture have been carried out. Design codes specify that the calculated DAF (dynamic amplification factor) should not exceed a certain value. However, it has been difficult to determine DAFs effectively from dynamic analysis, and thus no systematic approach has been suggested. The current study provides a guideline to determine DAFs reliably from the dynamic analysis results and summarizes the results by applying the method to an earth-anchored suspension bridge. In the study, DAFs were calculated at the location of four structural parts, girders, pylons, main cable and hangers, with variations in the rupture time.