• Journal of the Korean Society for Marine Environment & Energy
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• v.14 no.4
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• pp.224-229
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• 2011

Recently, the management of the marine invasive alien species introduced by ballast water has come to the core as an urgent task. Because, hazardous organisms cause harmful effects on the ecosystem. Hazardous organisms also negatively affect fisheries, commercial shipping activities, and marine resources. In this regard, IMO used to operate GloBallast, Ballast Water Risk Assessment System, in order to manage the introduction of invasive species by ballast water. GloBallast is constructed to assess the relative risk due to the movement of ballast water between nations, using the volume and the number of times of ballast water discharge, the environmental similarity between ports, and the abundance of hazardous species as the main factors. According to the results of the demo-operation of GloBallast, it was found out that the environmental similarity factor had affected most highly the results of risk assessment. Therefore, in this study, the correlation between the main factors used in GloBallast risk assessment were re-examined, and some methods were suggested in order to reflect these main factors in the risk assessment more reasonable.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.4
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• pp.117-123
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• 2013

In the recent cloud storage environment, the amount of SSD (Solid-State Drive) replacing with the traditional hard disk drive is increasing. Management of SSD for its space efficiency has become important since SSD provides fast IO performance due to no mechanical movement whereas it has wearable characteristics and does not provide in place update. In order to manage space efficiency of SSD, data de-duplication technique is frequently used. However, this technique occurs much overhead because it consists of data chunking, hasing and hash matching operations. In this paper, we propose new data de-duplication method using PRAM cache. The proposed method uses hierarchical hash tables and LRU(Least Recently Used) for data replacement in PRAM. First hash table in DRAM is used to store hash values of data cached in the PRAM and second hash table in PRAM is used to store hash values of data in SSD storage. The method also enhance data reliability against power failure by maintaining backup of first hash table into PRAM. Experimental results show that average writing frequency and operation time of the proposed method are 44.2% and 38.8% less than those of existing data de-depulication method, respectively, when three workloads are used.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.1
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• pp.49-60
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• 2018

The role of the botanical garden in securing biodiversity, responding to climate change, and sustainable development in modern cities is becoming more important. Private botanical gardens that lead the domestic botanical culture are declining due to complex reasons such as an increase of tourist destinations, lack of policy support, lack of introduction of advanced management strategies, and similar leisure activities to national and public botanical gardens. The Private Botanical Garden not only has a large number of plant species with high conservation value, but also provides various public utilities as a cultural and educational space and government efforts are needed to activate the operation of this amenity. The purpose of this study is to evaluate the value of public functions provided by private botanical gardens using the Contingent Valuation Method (CVM). In this way, the government aims to provide a basis for policy and institutional support for private botanical gardens. The main results are as follows. First, public utility functions provided by private botanical gardens were recognized as 'preservation' (23.4%), 'recreation and tourism' (17.5%) and 'research' (16.6%) in order of analytic hierarchy process (AHP). Second, 'heritage value' (33.0%) and 'existence value' (32.5%) were recognized as significant among the values provided by private botanical gardens. Third, the willingness to pay (WTP) to preserve the public functions of the private botanical garden was 12,234 won. Based on this, the economic value of all private botanical gardens in the whole country was estimated, resulting in about 233.8 billion won. There is a need to revise laws and regulations related to financial support for the revitalization and quality improvement of private botanical gardens. It is also necessary to establish a cooperative operating system between national, public and private botanical gardens.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.10
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• pp.4717-4737
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• 2017

Today, smart grids, smart homes, smart water networks, and intelligent transportation, are infrastructure systems that connect our world more than we ever thought possible and are associated with a single concept, the Internet of Things (IoT). The number of devices connected to the IoT and hence the number of traffic flow increases continuously, as well as the emergence of new applications. Although cutting-edge hardware technology can be employed to achieve a fast implementation to handle this huge data streams, there will always be a limit on size of traffic supported by a given architecture. However, recent cloud-based big data technologies fortunately offer an ideal environment to handle this issue. Moreover, the ever-increasing high volume of traffic created on demand presents great challenges for flow management. As a solution, flow aggregation decreases the number of flows needed to be processed by the network. The previous works in the literature prove that most of aggregation strategies designed for smart grids aim at optimizing system operation performance. They consider a common identifier to aggregate traffic on each device, having its independent static aggregation policy. In this paper, we propose a dynamic approach to aggregate flows based on traffic characteristics and device preferences. Our algorithm runs on a big data platform to provide an end-to-end network visibility of flows, which performs high-speed and high-volume computations to identify the clusters of similar flows and aggregate massive number of mice flows into a few meta-flows. Compared with existing solutions, our approach dynamically aggregates large number of such small flows into fewer flows, based on traffic characteristics and access node preferences. Using this approach, we alleviate the problem of processing a large amount of micro flows, and also significantly improve the accuracy of meeting the access node QoS demands. We conducted experiments, using a dataset of up to 100,000 flows, and studied the performance of our algorithm analytically. The experimental results are presented to show the promising effectiveness and scalability of our proposed approach.

• International Commerce and Information Review
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• v.18 no.3
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• pp.3-21
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• 2016

The thesis examines genealogical study of various aspects to overcome lots of problems which come by when we execute SWIFTNet TSU BPO. Practical implications regarding the innovation of electronic trade infrastructure are as follows. First, the shipping documents in the SWIFTNet TSU BPO are directly sent to an importer by an exporter after the baseline is confirmed. With this process itself, therefore, the bank cannot secure the account receivable. When initiating the SWIFTNet TSU BPO deal, it is needed to set regulations on the bank's account receivable security in the contract. Second, the SWIFTNet TSU BPO should also have an institutionally unified sharing platform with security, stability and convenience. It other words, it is needed to develop services which meet e-payment paradigm and international environments through continued analysis on market changes and flow. Third, the SWIFTNet TSU is useful in terms of promptness, reduction of risk in foreign exchange payment, cost reduction. Therefore, the SWIFT should be perfectly united and linked among the banks, importer and exporter to make the SWIFTNet TSU more convenient in countries around the world. Fourth, the SWIFT should be approached from the aspect of expansion of network and creation of a new business model through analysis on these problems with a worldwide perspective. At the same time, it is necessary to build a cooperative system to share information and promote comprehensive management for efficient operation.

• Korean Business Review
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• v.21 no.2
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• pp.195-214
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• 2008

In 2004, in order to create core competences and major growth drivers for endogenous regional developments, the Korean government adopted the policies for establishing regional innovation systems, The main organization for the policies is the regional innovation council which is composed of diverse groups of scholars, professionals, and government officials. The regional innovation council of Kang-won Province consists of a couple of sub-divisions such as Operation Committee, Administration Office, Planning and Moderation Department, Strategic Industry Department, Culture and Tourism Industry Department, Regional Industry Department, and Regional Human Resource Development Department. The primary roles and jobs are planning, reviewing, evaluating and finalizing regional innovation policies. However, because of conflicts with local government, insufficient budget problems, organization structure problems, and decision making process problems, the regional innovation councils could not perform their original roles and functions. They could not adopt radical or non-traditional strategies. Although it's failure, a lot of people recognize the importance of regional innovation councils' roles and functions, I believe there would be another regional innovation councils coming continuously which would be take more important roles and have more power over budgeting problems. The purpose of this article is to identify the primary sources of strategies and organization structure problems of the previous regional innovation councils and to provide a couple of answers. In this paper, the author primarily analyze the problems of the Kang-won innovation council. A couple of answers to the desirable organization structures and the desirable roles of regional innovation councils will be presented for discussion.

• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.102-108
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• 2012

This study has performed comparative analysis on characteristics of reservoirs in their use through correlation analysis on seasonal variation of water quality factors in agricultural reservoirs and multipurpose dams. Agricultural reservoirs show the high relationship between Chl-a and other water quality factors while the correlation among COD, BOD, and SS is strong in multipurpose dams. Agricultural reservoirs have the high relationship between various water quality factors in season such as Chl-a and pH ($R^{2}=0.294$) in Spring, pH and water temperature ($R^{2}=0.246$) in Summer, and Chl-a and BOD ($R^{2}=0.435$) in Fall, and between COD and BOD ($R^{2}=0.370$) in Winter, respectively, for Sapgyo reservoir while Chl-a and T-P ($R^{2}=0.739$) in Spring, T-P and SS ($R^{2}=0.876$) in Summer, and Chl-a and SS ($R^{2}=0.600$) in Fall, and between COD and SS ($R^{2}=0.998$) in Winter, respectively, for Seokmun reservoir. Boryeong dam has the strong relationship between T-P and SS ($R^{2}=0.511$) in Spring while the relation between COD and SS is high in other seasons with the values of $R^{2}$ of 0.362, 0.665, and 0.500 in Summer, Fall, and winter, respectively. The first and second water quality factors in relationship are COD and BOD in Sapgyo and Seokmun reservoirs, which is similar to the characteristics in Winter for multipurpose dams. Chl-a has no relationship with other water quality factors in Boryeong dam in operation for both flood control and low water regulation purposes. The result of this research is expected to provide contributions to the seasonal water quality control and analysis on characteristics for each reservoir by monitoring.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.1
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• pp.100-106
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• 2018

Since the concept of virtual currency called Bitcoin was announced in 2008, the blockchain technology, which is the basis of Bitcoin, is attracting attention as an important platform technology in the era of the 4th industrial revolution that can change our society in the future. Although Existing electronic financial transactions store and manage all transaction history at a reliable central organization such as government and bank, blockchain-based electronic financial transactions are composed of a distributed structure in which all participants participating in the transaction store and manage the transaction history, it is possible to secure transaction transparency while reducing system construction and operation costs. Besides the virtual currency that started with bit coins, the technology of these blockchains has been extended in various fields such as smart contracts and document management. The key technology area of this blockchain is security based on proven cryptographic technology to make it difficult to forge and hack, but there are security risks such as security vulnerabilities in the virtual currency trading service, We will discuss security risks in using virtual currency and discuss countermeasures. Especially security accidents of virtual currency exchanges are occurring frequently recently, the damage of users who trade the virtual currency is also increasing, we propose security threats and security countermeasures against virtual currency exchanges.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2004.11a
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• pp.158-161
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• 2004

In order for better management of a medical linear accelerator, the records of the operational failures of Varian CL2100C over ten years were analyzed. The failures were classified according to the involved functional subunits and each class was rated into three levels depending on operational conditions. The relationship between the failure rate and working ratio was investigated. Among the recorded failures ( total 587 failures), the most frequent failure, which was 20% of the total. was observed in the parts related to the collimation system including monitor chamber. Regrading to the operational conditions, the 2nd level of failures, that temporally interrupted treatments, was the most frequent. The 3rd level of failures, that interrupted treatment for more than several hours, was mostly caused by the accelerating subunit. The average life-time of a Klystron and Thyratron became shorter as the working ratio increased, which was 42 and 83% of the expected values, respectively. Recording equipment problems and failures in detail over a long period of time can provide a good knowledge of equipment function as well as the capability to forecast future failure. More rigorous equipment maintenance is required for old medical linear accelerator to avoid the serious failure in advance, and improve the patient treatment quality.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.11
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• pp.697-704
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• 2017

This study was carried out to investigate and alleviate the vibration problem of commercial high-speed trains. First, the measurement of the carbody vibration was performed, in order to determine the vibration level of the high-speed train. The measurement result showed that the vibration level of the driver cab was higher than that of the passenger car and that the vibration became bigger toward the trailing end of the train. The vertical vibration of the driver cab and passenger car was larger than the transverse vibration, and the maximum value of the vibration in the ballast section was larger than that in the concrete section. A dynamic analysis was carried out to improve the vibration of the KTX-Sancheon train. The results of the analysis showed that it is necessary to reduce the vibration of the driver cab and both ends of the passenger cars. To reduce the vibration of the driver cab, it was recommended that the stiffness of the secondary coil spring be reduced and the damping coefficient of the secondary vertical damper be increased. It was found that the failure of the suspension system could be the origin of the vibration problem of the high-speed train. The proper management of wheel wear plays an important role in the improvement of the operation efficiency and reduction of the carbody vibration of high-speed trains, and research is underway to change the present wheel profile to increase the mileage between wheel turning.