• Journal of Distribution Science
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• v.13 no.2
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• pp.15-24
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• 2015

Purpose - Foreign exchange risk control is in an important component in the international supply chain management. This study shows the importance of the reference period in forecasting future exchange rates with a specific illustration of KIKO currency option contracts, and suggests feasible preventive measures. Research design, data, and methodology - Using monthly Won-Dollar exchange rate data for January 1995~July 2007, I evaluate the statistical characteristics of the exchange rate for two sub-periods; 1) a shorter period after the East Asian financial crisis and 2) a longer period including the financial crisis. The key instrument of analysis is the basic normal distribution theory. Results - The difference in the reference period could lead to an unexpected development in contract implementation and a consequent financial loss. We may avoid foreign exchange loss by using derivatives such as forwards or currency options. Conclusions - We should consider not only level values but also the volatilities of financial variables in making a binding financial contract. Appropriate measures may differ depending on the specific supply chain pattern. We may extend the study with surveys on actual risk measures.

• Journal of Power Electronics
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• v.17 no.5
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• pp.1317-1326
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• 2017

The cascaded H-bridge (CHB) multilevel converter is a promising topology for large-scale photovoltaic (PV) systems. The output voltage over-modulation derived by the inter-module active power imbalance is one of the key issues for CHB PV systems. This paper proposed a dynamic power distribution strategy to eliminate the over-modulation in a CHB PV system by suitably redistributing the reactive power among the inverter modules of the CHB PV system. The proposed strategy can effectively extend the operating region of the CHB PV system with a simple control algorithm and easy implementation. Simulation and experimental results carried out on a seven-level CHB grid-connected PV system are shown to validate the proposed strategy.

• Tunnel and Underground Space
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• v.32 no.6
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• pp.530-548
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• 2022

The site selection process for deep geological disposal of high-level radioactive waste will be conducted in stages, and 103 evaluation parameters related to site selection have been proposed. In the field of rock mechanics and rock engineering, there are 33 evaluation parameters for intact rock, joint and rock mass, and they are applied in the basic and detailed investigation stages. In this report, uniaxial compressive strength, in-situ stress, joint distribution, and rock mass classification were selected as the main evaluation parameters, and among them, uniaxial compressive strength and in situ stress were selected as key evaluation parameters. Statistical techniques or regression analysis were performed for granite in Wonju and Chuncheon to evaluate the distribution range for the selected key evaluation parameters. The average of the uniaxial compressive strength in the Wonju area estimated through the posterior distribution is about 171 MPa, and about 123 MPa in the Chuncheon area. The maximum in situ stress acting in the Wonju area was less than 30 MPa and less than 40 MPa in the Chuncheon area. The direction of the maximum horizontal stress calculated by regression analysis was 101° in Wonju, and in the case of Chuncheon, it was 95°, respectiviely.

• Convergence Security Journal
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• v.21 no.1
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• pp.3-7
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• 2021

In quantum cryptographic communication based on quantum mechanics, each piece of information is loaded onto individual photons and transmitted. Therefore, it is impossible to eavesdrop on only a part, and even if an intruder illegally intercepts a photon and retransmits it to the recipient, it is impossible to send the same information to the photon by the principle of quantum duplication impossible. With the explosive increase of various network-based services, the security of the service is required to be guaranteed, and the establishment of a quantum cryptographic communication network and related services are being promoted in various forms. However, apart from the development of Quantum Key Distribution (QKD) technology, a lot of research is needed on how to provide network-level services using this. In this paper, based on the quantum encryption device, we propose an integrated data structure for transferring quantum keys between various quantum encryption communication network devices and realizing an encrypted transmission environment.

• The Journal of Asian Finance, Economics and Business
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• v.5 no.3
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• pp.169-178
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• 2018

This study aims is to explore of the theoretical concepts of regional imbalances and spatial inequality, analysis of spatial distribution of economic growth and identifying of "growth poles" for sustainable development in the regions of Kazakhstan. Based on the theoretical views, we conclude that the key direction of regional policy is the search and development of "growth poles", which will distribute their potential equally to backward regions. The authors propose the methodological tools for presenting a standard form of evaluation of spatial distribution and inequality of the regions of Kazakhstan. This study confirms the importance of using of proposed methods and its application for objectively and realistically defines "growth poles" for sustainable development. Further, the obtained results showed the distribution of Kazakhstan's regions by economic growth and specialization with using modified index of KDI. According to the results of this theoretical and empirical study proved that distribution of the regions of Kazakhstan and results of KDI indexes shows that the spatial differentiation of economic development, but its level and dynamics are different in different respects. In addition, according to the conducted survey, we conclude that one of the most important tasks is sustainable growth based on "growth poles" for sustainable development.

• Journal of the Optical Society of Korea
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• v.7 no.1
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• pp.1-6
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• 2003

Integration and miniaturization at the systems level are key requirements for photonics applications. Here, we describe the concept of planar integration of free-space optical systems and its use as an optical interconnection technology. Two specific applications will be considered, a parallel chip-to-chip interconnect and an optical clock distribution network.

• Journal of Distribution Science
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• v.18 no.2
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• pp.5-15
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• 2020

Purpose : Today's retailers are integrating new VR technology into their new marketing strategies. Thus, this research aims to understand the role of virtual experiences in the circumstance of sales channels. Research design, data and methodology : Our model hypothesizes that five key factors determine the consumer experience of VR in the virtual retailing context: smartness, vividness, interactivity, playfulness, escape. Information access and flow are mediating variables that connect key drivers and VR satisfaction. Information access and flow then give influence to satisfaction towards VR. Satisfaction serves as a mediator that determines changes in consumer's dual intention: intention to revisit VR and intention to visit the real site. Results : According to the test results, every path except the relationship between information access and satisfaction of VR is accepted as expected at the significance level of 0.05. Conclusions : This research emphasizes the potential importance of VR and continue VR marketing research as an advent research area. Through the dual-path model, this study found that the primary function of VR is information access and flow experience. This result shows that most VR users value emotional benefits rather than rational benefits provided by VR. Finally, the satisfaction of VR can stimulate both the intention to use the VR and the intention to visit real mall.

• Computers and Concrete
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• v.15 no.2
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• pp.305-319
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• 2015

On mesoscopic level, concrete can be treated as a three-phase composite material consisting of mortar, aggregates and interfacial transition zone (ITZ) between mortar and aggregate. A lot of research has confirmed that ITZ plays a crucial role in the mechanical fracture process of concrete. The aim of the present study is to propose a numerical method on mesoscale to analyze the failure mechanism of reinforced concrete (RC) structures under mechanical loading, and then it will help precisely predict the damage or the cracking initiation and propagation of concrete. Concrete is meshed by means of the Rigid Body Spring Model (RBSM) concept, while the reinforcing steel bars are modeled as beam-type elements. Two kinds of RC members, i.e. subjected to uniaxial tension and beams under bending, the fracture process of concrete and the distribution of cracks, as well as the load-deflection relationships are investigated and compared with the available test results. It is found that the numerical results are in good agreement with the experimental observations, indicating that the model can successfully simulate the failure process of the RC members.

• Korea Journal of Hospital Management
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• v.5 no.2
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• pp.40-58
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• 2000

Nurses are medical personnel, who play a key role in supporting patient care, so it is important to supply them adequately in balance with ever increasing medical demand. But there appears severe shortage of nurses in some hospitals because of their uneven distribution, especially in small sized-hospitals and rural-hospitals. As nationwide distorted distribution of nurses in Korea is just like what monopsony model(a kind of market structure model) tells us, it is attempted to explain this situation of nurse labor market in Korea on the basis of monopsony model and presented in this paper. Specifically, determinants of nurse wage and the level of their relative employment were examined, and monopsony impact on their wage and the level of relative employment controlling those determinants were studied. Major results of this study arc as follows. The most important determinant of nurse wage level in this study was the wage level of a local community where each hospital located Hospital owner's characteristics an educational function of each hospital were also important factors. With these factor controlled, it was found that monopsony power of each hospital was negativel associated with nurse wage level as expected. 1% increase in monopsony power of hospital(measured by Herfindah-Hirschman Index) reduced nurse wage by $5,674{\sim}19,19$ won(in Korean currency). With regard to the level of relative employment, the most important determinant wa the capacity for supplying nurses of the local community. Again, hospital owner characteristics and educational function of each hospital were also important. With these factors controlled, it was found that monopsony power of each hospital was negative associated with the number of nurses per bed, as expected. 1% increase in monopsony power of each hospital(again measured by Herfindah-Hirschman Index) reduced the number of nurses per 100 bed as much as $0.46{\sim}0.67$. In conclusion. structural factors of nurse labor market influence the instability of nurse labor supply in Korea. Further consideration for these market structural characteristics needed for policy making related to nurse resource allocation.

• Steel and Composite Structures
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• v.39 no.3
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• pp.229-241
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• 2021

This work focused on aluminum foam sandwich (AFS) with different foam core densities and different face-sheet thicknesses subjected to constant amplitude three-point bending cyclic loading to study its fatigue performance. The experiments were conducted out by a high frequency fatigue test machine named GPS-100. The experimental results showed that the fatigue life of AFS decreased with the increasing loading level and the structure was sensitive to cyclic loading, especially when the loading level was under 20%. S-N curves of nine groups of AFS specimens were obtained and the fatigue life of AFS followed three-parameter lognormal distribution well. AFS under low cyclic loading showed pronounced cyclic hardening and the static strength after fatigue test increased. For the same loading level, effects of foam core density and face-sheet thickness on the fatigue life of AFS structure were trade-off and for the same loading value, the fatigue life of AFS increased with aluminum foam core density or face-sheet thickness monotonously. Core shear was the main failure mode in the present study.