• Journal of Distribution Science
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• v.12 no.10
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• pp.123-128
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• 2014

Purpose - The purpose of the study is to reexamine the price fairness as practiced by low cost airlines, as a consumer has to experience such inconveniences as inferior airport transportation, extra fees on in-flight meals, and non-negotiable seats, and consumers evaluate such experiences keeping in mind their total costs. This evaluation includes price fairness and allows a reasonable and overall consideration of factors of low cost airlines. It tries to set up a measurement of the indicators consumers' perceptions of price fairness academically as it adapts price fairness to airline services which are renowned for price volatility. Research design, data, and methodology - The research proposes an alternative pricing strategy for the long term profit of low cost airlines after going over conflicts between the traditional theory of consumers' price perception mechanism and flexible fair policy of low cost airlines. It was meaningful when it relates to the early stage of the business, while it enhances the risks relating to the long term survival of low cost airlines. In addition, it is significant as it highlights the negative influences on consumers' perceptions of price fairness, as low cost airlines run on extremely low cost perspectives. Results - The results of the research provide insight into four perspectives, as consumers' perceptions of price fairness are influenced by the frequency and range of price changes and services. The first perspective is that it would lead to positive price evaluation when a low cost airline cuts prices frequently with little changes than one big change. It also would lead to the same result when it comes to necessary services. The second perspective is that one big increase of price would rather undermine the negative aspects of price changes than those of several smaller ones. The third perspective is that additional services would be good to consumers' perceptions of price fairness as compared to discount benefits with respect to the cost. Finally, a low cost airline should consider that consumers will change airlines or defer their flight schedule if the flight fares increase beyond their limits. Conclusions - Low cost airlines should reconsider their pricing policies for services that were provided free earlier. A consumer would not like discount benefits when made to pay for services that were, for long, free of charge. If a low cost airline can provide services with no charge, it should improve volumes if the costs are standardized and, moreover, should consider the charging fees. Alternatively, a consumer can choose between services and fair discount. Low cost airlines are implementing sales promotion strategies, as the competition is more intense than it used to be. In these days, they should regard services over sales promotion, as consumers may prefer to spend money on good premium services. Some differentiation in services could create a good market position for the airlines and, hence, good financial performance.

• Journal of KIISE:Information Networking
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• v.29 no.5
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• pp.583-594
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• 2002

Assuring the security of group communications such as tole-conference and software distribution requires a common group key be shared among the legal members in a secure manner. Especially for large groups with frequent membership change, efficient rekey mechanism is essential for scalability. One of the most popular ways to provide sealable rekey is to partition the group into several subgroups. In this paper, we propose a two-layered key management scheme which combines DEP and CBT, a protocol in which subgroup manager cannot access the multicast data and another that has a multi-core, respectively. We also select sub-group key management protocols suitable for our structure and design new rekey protocols to exclude the subgroup managers from the multicast data. Compared to previous protocols based on CBT, our scheme provides forward secrecy, backward secrecy and scalability. This would reduce the number of encryption and decryption for a rekey message and would improve the efficiency number of rekey messages and the amount of information related to group members that group managers must maintain compared to DEP.

• Journal of Distribution Science
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• v.11 no.5
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• pp.55-62
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• 2013

Purpose - This study aims to determine the problems and limitations of the Commercial Area Activation System, which was created by a special law for promoting traditional markets and shopping districts to revitalize and efficiently manage the central commercial area in different regions. We also suggest different options for its improvement. Research design, data, and methodology - We also look into the problems of which is being promoted as a demonstration project, from the aspects of legal text and guidelines. Results - The current commercial area activation system has several problems. First, the establishment of a comprehensive basic plan on the commercial area activation is not a requirement. Second, the benefit principle should be established to prevent the moral laxity of merchants who serve important roles in the main components of the commercial area activation business when they conduct their business. Third, the current special law constrains the commercial management organization, as under the civil law yields a limitation on finding a profitable business model. Fourth, to efficiently, constructing a system that links the other central government businesses and is needed. into a regional development budget or a budget for funding small businesses that the central government can control, which is effective. Further, we offer some suggestions for medium- and long-term policies. First, an integrated coordination mechanism at the central office level should be installed while setting the basic policy to revitalize the Based on this policy, local governments need a system that exclusively based on the after establishing a comprehensive plan for urban regeneration and getting approval from the integration organization. Second, a system that enables an understanding of the problems with business promotion by monitoring the procedure of supporting projects and regularly assessing business achievements is needed. Third, a plan is needed for resolving conflicts between various interested parties that adopts the commercial area activation system for carrying out a total redevelopment of the commercial area where small shops are densely located. A market maintenance project has been conducted as a means to recover our traditional market, which was economically depressed, and to revive the local economy, but it is mostly conducted in the form of reconstruction or redevelopment and represents the interests of landowners and merchants. Thus, it is most likely to lead to a gradual disappearance of traditional markets. Conclusions - This study looks primarily into the problems that appeared in the legal text or the guidelines regarding the direction of improvement of the commercial area activation business that has been going on as a demonstration project since 2011 and suggests some solutions.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.179-186
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• 2004

Introduction of wave model, considered the effect of shoaling, refraction, diffraction, partial reflection, bottom friction, breaking at the coastal waters of complex bathymetry, is a very important factor for most coastal engineering design and disaster prevention problems. As waves move from deeper waters to shallow coastal waters, the fundamental wave parameters will change and the wave energy is redistributed along wave crests due to the depth variation, the presence of islands, coastal protection structures, irregularities of the enclosing shore boundaries, and other geological features. Moreover, waves undergo severe change inside the surf zone where wave breaking occurs and in the regions where reflected waves from coastline and structural boundaries interact with the incident waves. Therefore, the application of mild-slope equation model in this field would help for understanding of wave transformation mechanism where many other models could not deal with up to now. The purpose of this study is to form a extended mild-slope equation wave model and make comparison and analysis on variation of harbor responses in the vicinities of Pohang Old Harbor and Pohang New Port, etc. due to construction of New Port in Youngil Bay. This type of trial might be a milestone for port development in macroscale, where the induced impact analysis in the existing port due to the developemnt could be easily neglected.

• Journal of the Korean Society for Railway
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• v.16 no.1
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• pp.7-13
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• 2013

A scaled version of a roller rig is developed to demonstrate the dynamic characteristics of a railway vehicle for academic purposes. This rig is designed based on Jaschinski's similarity law. It is scaled to 1/10 of actual size and allows 9-DOF motion to examine the up and down vibration of a train set. The test rig consists of three sub-hardware components: (i) a driving roller mechanism with a three-phase AC motor and an inverter, (ii) a bogie structure with first and second suspensions, and (iii) the vehicle body. The motor of the rig is capable of 3,600rpm, allowing the test to simulate a vehicle up to a maximum speed of 400Km/hr. Because bearings and joints are properly connected to the sub-structures, various motion analyses, such as a lateral, pitching, and yawing motion, are allowed. The slip motion between the rail and the wheel set is also monitored by several sensors mounted in the rig. After the construction of the hardware, an experiment is conducted to obtain the natural frequencies of the dynamic behavior of the specimen. First, the test rig is run and data are collected from six sets of accelerometers. Then, a numerical analysis of the model based on the ADAMS program is derived. Finally, the measurement data of the first three fundamental frequencies are compared to the analytical result and the validation of the test rig is conducted. The results show that the developed roller rig provides good accuracy in simulating the dynamic behavior of the vehicle motion. Although the roller rig designed in this paper is intended for academia, it can easily be implemented as part of a dynamic experiment of a bogie and a vehicle body for a high-speed train as part of the research efforts in this area.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.43 no.1 s.343
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• pp.27-36
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• 2006

Conventional delay-insensitive (DI) data encodings usually require 2N+1 wires for transferring N-bit. To reduce complexity and power dissipation of wires in designing a large scaled chip, an encoder and a decoder circuits, where N-bit data transfer can be peformed with only N+l wires, are proposed. These circuits are based on a quasi delay-insensitive (QDI) model and designed by using current-mode multiple valued logic (CMMVL). The effectiveness of the proposed data transfer mechanism is validated by comparisons with conventional data transfer mechanisms using dual-rail and 1-of-4 encodings through simulation at the 0.25 um CMOS technology. In general, simulation results with wire lengths of 4 mm or larger show that the CMMVL scheme significantly reduces delay-power product ($D{\ast}P$) values of the dual-rail encoding with data rate of 5 MHz or more and the 1-of-4 encoding with data rate of 18 MHz or more. In addition, simulation results using the buffer-inserted dual-rail and 1-of-4 encodings for high performance with the wire length of 10 mm and 32-bit data demonstrate that the proposed CMMVL scheme reduces the D*P values of the dual-rail encoding with data rate of 4 MHz or more and 1-of-4 encoding with data rate of 25 MHz or more by up to $57.7\%\;and\;17.9\%,$ respectively.

• Journal of Digital Convergence
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• v.16 no.6
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• pp.233-240
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• 2018

The study aimed to evaluate the effects of the EMDR-IGPT(Eye movement desensitization and reprocessing-integrative group treatment protocol) on the depression, anxiety, post traumatic stress, self-esteem in graduate nursing students. A quasi-experimental study employing a nonequivalent control group and pre-post design was conducted. The participants were graduate nursing students from C university (Experimental group=22, Control group=28). The experimental group participated in the 8 session-EMDR-IGPT for 8 weeks, while control group were treated by waitlist. Data were analyzed using ${\chi}^2-test$, independent t-test, with SPSS 24.0 program. There were significant differences in anxiety(t=-2.50, p<.05) and self-esteem(t=20.78, p<.01) of participants between experimental group and control group after completion of 8 session-EMDR-IGPT. The results indicate that EMDR-IGPT can be used to improve anxiety and self-esteem of graduate nursing students. Furthermore, further study needs to identify the mechanism of the effects of the program.

• Journal of the Korean Geotechnical Society
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• v.33 no.3
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• pp.29-36
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• 2017

It has been known that rockbolt is one of important supports improving the support capacity with shotcrete in NATM tunnel. Also, it is necessary for the inclined system bolting to enhance the efficiency of installation in case of a narrow space such as cross passage and enlargement tunnel. However, there is no profound technical study for the effect of inclined rockbolt of systematic installation on the support mechanism and ground behaviour in NATM tunnel. In this study, the effects of the length and installation angle of rockbolt on the characteristics of support and ground reinforcement were analyzed by using 3D finite element numerical study. Through the numerical results for the parametric modelling of inclined rockbolt, the characteristics of mechanical behaviors between the axial force of rockbolt and the effect of ground reinforcement in regard to the various factors of the length and installation angle of rockbolt were verified and reviewed thoroughly. Also, it was shown that the installation angle of rockbolt for enhancing the arching effect in NATM tunnel was $45^{\circ}$, and the difference of the reinforcing effect for support between the installation angles of $75^{\circ}$ and $90^{\circ}$ was insignificant. The additional numerical studies for various condition would be carried out for practical design guideline of inclined rockbolt.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.595-602
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• 2006

An experimental study was conducted to investigate seismic behaviour of post-tensioned(PT) exterior slab-column connections used for the purpose to resist gravity loads only. For these, 2/3-scale, two PT post-tensioned exterior connections with two different tendon arrangement patterns and one conventional reinforced concrete(RC) exterior connection was tested under quasi-static, uni-directional reversed cyclic loading. During the lateral testing, gravity forces transferred to the column were kept constant to closely simulate a moment to shear ratio of a real building. One of the objectives of this study was to assess the necessity and/or the quantity of bottom bonded reinforcement needed to resist moment reversal which would occur under significant inelastic deformations of the adjacent lateral force resisting systems. The ACI 318 and 352 provisions for structural integrity were applied to provide the bottom reinforcement passing through the column for the specimens. Prior test results were also collected to conduct comparative studies for some design parameters such as the tendon arrangement pattern, the effect of post-tensioning forces and the use of bottom bonded reinforcement. Consequently, the impact of tendon arrangement on the seismic performance of the PT connection, that is lateral drift capacity and ductility, dissipated energy and failure mechanism, was considerable. Moreover, test results showed that the amount of bottom reinforcement specified by ACI 352. 1R-89 was sufficient for resisting positive moments arising from moment reversal under reversed cyclic loads. Shear strength of the tested specimens was more accurately predicted by the shear strength equation(ACI 318) considering the average compressive stress over the concrete($f_{pc}$) due to post-tensioning forces than that without considering $f_{pc}$.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.3B
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• pp.360-374
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• 2004

The OSPF protocol is the most widely used Interior Gateway Routing Protocol. Therefore, for the reliability of behavior of gigabit swiching routers, it is essential to guarantee the interoperability and the safety of the OSPF protocol. In this paper, we analyze the standard document of the OSPF protocol, so that we provide a formal specification that specifies the protocol behaviors by detailed design level using the algebraic formal method. By referring available source codes of the OSPF protocol, we supplement the formal specification to express more detailed behaviors that is not specified definitely in the standard. We also formally verify the interoperability and the safety of the protocol state machine of the specification. By showing that the formal specification specify all of the states and the transition events that appear in the standard document of the OSPF protocol, we prove that the state machine has the completeness, and prove it has the interoperability. To prove that the specification of the protocol has the safety, we formally verify the reachability, the liveness, the livelock-free property, and the deadlock-free property. As a result, we prove the protocol has the consistency. The specification and the validation are also effective to the OSPF Version 3 that inherit the protocol mechanism of the OSPF Version 2.