• The Journal of Fisheries Business Administration
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• v.37 no.2 s.71
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• pp.111-139
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• 2006

Cold storage warehouse industry in Japan has been extended in its scale in terms of both the number of storages and cold storage capacity in order to meet the extended reproduction of the marine products industry. However, increasing total amount of the stored goods since mid 80s led to relative decrease of marine products while the number of storages was remained the same or decreased, though cold storage capacity was gradually increased and is maintained the increase of the average cold storage capacity. As structural change in the cold storage warehouse industry emerges, cold storage warehouses require new approach to individual storage management with 1)diversity of the stored goods; 2) more competition due to increase of the cold storage capacity; and 3) sizing of the average cold storage capacity. Therefore, this study analyzed how cold storage warehouse management activity with individual storage sizing changes; and significance of sizing and functional change in cold storage warehouses experiencing sizing, by observing leading cold storage warehouse industry of the metropolitan area in Japan. In conclusion, reorganization of cold storage warehouse industry in the metropolitan area in Japan can be summarized as follows: First, competition among cold storage warehouses in the metropolitan area in Japan is not simply limited to storage industry but extended to establishment and securing physical distribution function. Second, since cold storage warehouse industry is in Scrap & Build phase, decision of management executives on whether taking direction to maintain/continue enhancement of physical distribution function may cause drastic reorganization in the cold storage warehouse industry, Third, since profit of physical distribution management based on cold storage warehouses is insignificant, it is not easy to accomplish expected management outcome, Fourth, today's cold storage warehouse industry mainly characterized by diversity of the stored goods needs facility reorganization with comprehensive and functional integration covering from F class cold storage capacity to F&C class.

• Archives of design research
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• v.13 no.1
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• pp.227-235
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• 2000

From environmental point of view, the foreign exchange crisis has motivated the Government to make the positive promoting policy for holding the foreign currency, leading to a series of small companies' bankruptcy due to foreign distribution companies' advance into our country, creating a new consuming culture. Though inaugurations have been vividly in progress in the aftermath of recession, reduced staffs and arranged layoff, their way gives priority to the reduced frame of the existing method rather tham the development or improvement of a new distribution. It is difficult to attain the sales goal unless a marketing analysis is not properly made, due to store managers' lack in expertism of management. In view of culture, the change of retail stores is imperative at the point that the type of consumers' purchase is rapidly changing and a more positive business system is needed. preventing an opportunistic loss of management through the analysis of outcome such as consumer management, sales management and account management by using computers. In view of design. the display in sale is to interpret products more charmingly, and should make interpretation accurately by selecting an important theme. For this, taking the store for valuables for instance. the progress on the effective foundation and store dinic business by presenting the design blue print can be made, and the strategy coping with the foreign distribution market's rush into Korea can be established. through the advanced store management.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.11
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• pp.4268-4290
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• 2015

Future mobile communications face enormous challenges as traditional voice services are replaced with increasing mobile multimedia and data services. To address the vast data traffic volume and the requirement of user Quality of Experience (QoE) in the next generation mobile networks, it is imperative to develop efficient content distribution technique, aiming at significantly reducing redundant data transmissions and improving content delivery performance. On the other hand, in recent years cloud computing as a promising new content-centric paradigm is exploited to fulfil the multimedia requirements by provisioning data and computing resources on demand. In this paper, we propose a cooperative caching framework which implements State based Content Distribution (SCD) algorithm for future mobile networks. In our proposed framework, cloud service providers deploy a plurality of cloudlets in the network forming a Distributed Cloud Service Network (DCSN), and pre-allocate content services in local cloudlets to avoid redundant content transmissions. We use content popularity and content state which is determined by content requests, editorial updates and new arrivals to formulate a content distribution optimization model. Data contents are deployed in local cloudlets according to the optimal solution to achieve the lowest average content delivery latency. We use simulation experiments to validate the effectiveness of our proposed framework. Numerical results show that the proposed framework can significantly improve content cache hit rate, reduce content delivery latency and outbound traffic volume in comparison with known existing caching strategies.

• Journal of Digital Convergence
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• v.11 no.3
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• pp.209-219
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• 2013

Smart phone environment have an effect on consumer life style, as well as advances in technology. In this paradigm shift on digital convergence make change to commodities, services, and distribution channels for consumers. HomePlus wholesale that is representative distribution company in Korea launched the new distribution channel model that combined off-line store with online store and mobile shopping system called 'smart mobile virtual store'. That is highly praised by abroad media and festivals. This study is an exploratory study on consumer-centric smart mobile virtual store of HomePlus. There are value and chance for developing the new digital distribution model, in this study, because the case study and evaluation of consumers is important in this momentous time.

• Journal of Hydrogen and New Energy
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• v.23 no.5
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• pp.468-475
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• 2012

A proper stacking force and assembly are important to the performance of fuel cell. Improper assembly pressure may lead to leakage of fuels and high interfacial contact resistance, excessive assembly pressure may result in damage to the gas diffusion layer and other components. The pressure distribution of gas diffusion layer is important to make interfacial contact resistance less for stack performance. To analyze the influence of design parameter factors for pressure distribution, and to optimize stack design, DOE (Design of Experiment) was used for polymer electrolyte membrane fuel cell stack pressure test. As commonly known, the higher clamping force improves the fuel cell stack performance. However, non-uniformity of stress distribution is also increased. It shows that optimization between clamping force and stress distribution is needed for well designed structure of fuel cell stack. In this study, stack design optimization method is suggested by using FEM (Finite Element Methode) and DOE for light-weighted fuel cell stack.

• Journal of Hydrogen and New Energy
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• v.29 no.6
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• pp.654-660
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• 2018

The dependence on global fossil fuels has been gradually reducing all over the world. Some countries which recognized the important of environmental values were joining to carry out international GHG goals. Our country has also participated with high targets (37% reduction compared to BAU 2030 years). So we need to supply materials of lower GHG value such as a bio-diesel. Bio-alcohol is one of the similar bio-fuels that can be reducing GHG. A lot of countries had tried to commercialize through various R&D for bio-alcohol. In this study, we analyzed the fuel characteristics of bio-alcohol fuel produced by domestic technology. And we evaluated a possibility to use as vehicle fuel through mixing of bio-alcohol and gasoline. The mixed fuels were satisfied with 2.3 wt% of oxygen content that is standard of the petroleum and petroleum alternative fuel business Act. We tried to evaluate a emission characteristic of vehicle by mixed fuel. In accordance with the results we tried to find a correlation between fuel and emission.

• Journal of Korea Water Resources Association
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• v.52 no.5
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• pp.373-380
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• 2019

In this study, the optimum pump operation technique is suggested to decrease the damage rate of water distribution system. Pump operation system was developed to achieve the effective pump operation. Pressure sensors which can communicate with pumps are installed at the end of water distribution system. Pump operation system can control the pressure of water pump according to data sent from the pressure sensors. Therefore, water distribution system can reduce the pressure and maintain enough pressure which can supply the demand of water users. For proving effectiveness of new system, reliability model was introduced to compare the results of damage rates between the maintaining high pressure and selective pressure in water pump. Unsteady analysis was conducted with several scenarios. And the results were used to calculate the probability of pipe breakage. From the results, it was found that new pump operation system can reduce the energy usage and probability of pipe breakage by applying to pumps.

• Journal of Hydrogen and New Energy
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• v.34 no.4
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• pp.358-368
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• 2023

The fuel cell market is expected to grow rapidly. Therefore, it is necessary to scale up fuel cells for buildings, power generation, and ships. A multi-stack system can be an effective way to expand the capacity of a fuel cell. Multi-stack fuel cell systems are better than single-stack systems in terms of efficiency, reliability, durability and maintenance. In this research, we developed a residential fuel cell stack and system model that generates electricity using the fuel cell-photovoltaic hybrid system. The efficiency and hydrogen consumption of the fuel cell system were calculated according to the three proposed power distribution methods (equivalent, Daisy-chain, and optimal method). As a result, the optimal power distribution method increases the efficiency of the fuel cell system and reduces hydrogen consumption. The more frequently the multi-stack fuel cell system is exposed to lower power levels, the greater the effectiveness of the optimal power distribution method.

• Journal of the Korea Society of Computer and Information
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• v.9 no.3
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• pp.177-182
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• 2004

The existing group key management architectures applied to a small scale routing protocols may have many overheads with key distribution. Therefore this paper proposes a group key management protocol in PIM-SM multicast group communication. This method divide multicast groups with RP, and subgroup key managers are established in each RP and can be transmitted groups keys. And this does not have needs of the data translation and the new key distribution for path change. This does not have needs of the data translation and the new key distribution for path change, so the data transmission time can be reduced.

• Proceedings of the Korean Reliability Society Conference
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• 2001.06a
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• pp.311-319
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• 2001

All indices that are now in use assume normally distributed data, and any use of the indices on non-normal data results in inaccurate capability measurements. Therefore, $C_{s}$ is proposed which extends the most useful index to date, the Pearn-Kotz-Johnson $C_{pmk}$, by not only taking into account that the process mean may not lie midway between the specification limits and incorporating a penalty when the mean deviates from its target, but also incorporating a penalty for skewness. Therefore we propose, a new process capability index $C_{psk}$( WV) applying the weighted variance control charting method for non-normally distributed. The main idea of the weighted variance method(WVM) is to divide a skewed or asymmetric distribution into two normal distribution from its mean to create two new distributions which have the same mean but different standard distributions. In this paper we propose an example, a distribution generated from the Johnson family of distributions, to demonstrate how the weighted variance-based process capability indices perform in comparison with another two non-normal methods, namely the Clements and the Wright methods. This example shows that the weighted valiance-based indices are more consistent than the other two methods In terms of sensitivity to departure to the process mean/median from the target value for non-normal process.s.s.s.