• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.142-146
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• 2008

Titanium silicalite-1 catalyst was prepared using a $SiO_2-TiO_2$ xerogel and applied to allylchloride (ALC) epoxidation by $H_2O_2$ as oxidant in a batch reactor. The reaction temperature was varied from 25 to $55^{\circ}C$, and the concentrations of ALC and $H_2O_2$ were changed from 0.2 to 3 M and from 0.2 to 1.5 M, respectively. The kinetic data obtained were applied to the power rate law, Eley-Rideal, and a Langmuir-Hinshelwood model, and power rate law fits the experimental data best. Activation energy was 27.9 kJ/mol, and the reaction orders with respect to $H_2O_2$ and ALC were determined to be 0.41 and 0.52, respectively.

• The Journal of Engineering Geology
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• v.18 no.2
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• pp.207-214
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• 2008

We conducted uniaxial consolidation tests in mudstone samples with different clay content, in order to investigate time-dependent deformation and its characteristics. A significant amount of time-dependent strain was observed at a constant stress level immediately after a jump of stress was applied. For a given mudstone, the amount of time-dependent deformation was nearly proportional to the increment of stress, suggesting a linear viscous rheology. The amount of time-dependent strain increases with clay content, implying that clay plays an important role in creep of the unconsolidated mudstone. A power-law model was suitably applied to our results, suggesting that a short-term prediction of time-dependent deformation of the mudstone is tentatively feasible.

• Informatization Policy
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• v.24 no.3
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• pp.42-66
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• 2017

This study investigated the ecological change of public software industry, comparing the pre and post structure of industry network based on the application of the regulation restricting large company participation in public software market. For this purpose, we used big data of the software market from Korea Public Procurement Service and used the SNA(Social Network Analysis) methodology which is being actively used in the area of social science recently. Finally, we highlighted the contribution of open public data. By analyzing order and contract data of the public software industry for 3 years - from 2013 to 2015 - we found out two main things. First, we observed that Power Law distribution had been going on in the public software industry, regardless of the external impact of regulation. Second, despite the existence of such Power Law distribution, we also observed the ecological change of industry structure from year to year. We presented the implication of such findings and discussed the advantage of open public data as the original motivator of this study.

• Applied Chemistry for Engineering
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• v.23 no.2
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• pp.204-209
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• 2012

In this study, kinetics data was obtained for steam reforming reaction of ethane over the commercial ruthenium catalyst. The variables of ethane steam reforming were the reaction temperature, partial pressure of ethane, and steam/ethane mole ratio. Parameters for the power rate law kinetic model and the Langmuir-Hinshelwood model were obtained from the kinetic data. Also, sizing of steam reforming reactor was performed by using PRO/II simulator. The reactor size calculated by the power rate law kinetic model was bigger than that of using the Langmuir-Hinshelwood model for the same conversion of ethane. Reactor size calculated by the Langmuir-Hinshelwood model seems to be more suitable for the reactor design because the Langmuir-Hinshelwood model was more consistent with the experimental results.

• KNOM Review
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• v.21 no.2
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• pp.18-25
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• 2018

Since the development of block-chain technology by Satoshi Nakamoto and Bitcoin pioneered a new cryptocurrency market, a number of scale of cryptocurrency have emerged. There are crimes taking place using the anonymity and vulnerabilities of block-chain technology, and many studies are underway to improve vulnerability and prevent crime. However, they are not enough to detect users who commit crimes. Therefore, it is very important to detect abnormal behavior such as money laundering and stealing cryptocurrency from the network. In this paper, the characteristics of the transactions and user graphs in the Bitcoin network are collected and statistical information is extracted from them and presented as plots on the log scale. Finally, we analyze visualized plots according to the Densification Power Law and Power Law Degree, as a result, present features appropriate for detection of anomalies involving abnormal transactions and abnormal users in the Bitcoin network.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.7
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• pp.914-924
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• 2020

In this study we developed artificial network generation model, which can generate on-line social network. The suggested model can represent not only scale-free and small-world properties, but also can produce networks with various values of topological characteristics through controlling two input parameters. For this purpose, two parameter K and P are introduced, K for controlling the strength of preferential attachment and P for controlling clustering coefficient. It is found out on-line social network can be generated with the combinations of K(0~10) and P(0.3~0.5) or K=0 and P=0.9. Under these combinations of P and K small-world and scale-free properties are well represented. Node degree distribution follows power-law. Clustering coefficients are between 0.130 and 0.238, and average shortest path distance between 5.641 and 5.985. It is also found that on-line social network properties are maintained as network node size increases from 5,000 to 10,000.

• The Korean Society of Law and Medicine
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• v.9 no.2
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• pp.77-107
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• 2008

In Republic of Chaina (Taiwan), Natural Death Act named "Anning Huauhe Yiliao Tiaoli" which means palliative and hospice care act was enacted in year of 2000. And enforced in the same year. Many scholars say that Taiwan's Act took Many U.S.A.'s acts such as 'Federal Patient Self-Determination Act 1990', 'California Natural Death Act 1976' and 'Washington Natural Death Act 1979' for a model. Taiwan's Act adopts a few outstanding systems - 'advance declarations' including 'living will' and 'durable power of attorney for health care', 'family-determination system' for a patient who is in a persistent unconscious state. This paper disusses this Act. 'The content is as follow: 1. A background of legislation. 2. The purpose of legislation. 3. The concept of terms. 4. Patient's self-determination. 5. Subrogated determination by family. 6. Keeping documents. 7. Punitive provision. 8. The relationship with euthanasia. 9. Controversial issues.

• Transactions of The Korea Fluid Power Systems Society
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• v.4 no.1
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• pp.13-17
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• 2007

The brake gain adaptive wheel slip controller for a vehicle is designed in this paper. The brake gain from braking pressure to braking torque defined by friction coefficient, friction area and effective friction radius is estimated by the adaptive law based on the wheel slip dynamics. And the wheel slip controller is designed based on the estimated brake gain. The robustness of the designed controller is analyzed using Lyapunov function and the convergence of brake gain is verified. Proposed wheel slip controller is verified via CarSim simulation with two kinds of desired wheel slip ratio.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.19
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• pp.96-118
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• 2003

Government tries to revise the article 25 in Korea Maritime Transport Act which describes subject of coastal carriage for exported-imported container cargoes. The subject of coastal carriage will be replaced coastal carrier by ocean liner carrier according to the revised article 25. By adopting the revised article, coastal shipping industry will be deteriorated in terms of returns on investment, sales and etc. Even though the revision is inevitable to harmonize the flow of exported-imported container cargo movement, coastal shipping industry should be developed and restructured to get competitive power and to set up an efficient international logistics system. To enhance competitive power of coastal shipping companies successfully, government must realize the importance of coastal shipping, and aid the industry through various methods such as arrangement of law and regulation, indirected financial assistance, decrease of tax rate, etc.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.58
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• pp.267-286
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• 2013

Origin verification is regarded most essential for FTA performance administration. This administration is divided into direct and indirect system where Korea has adapted indirect system to Korea-EU FTA while direct system to Korea-USA FTA. A comparative analysis was conducted on the system of origin verification and provisions contained in preferential tariff law of each countries. The study finds that Korean origin verification system is a bit lack of procedural provision resulting in less protection of domestic trader's rights. Another point is that Korean Customs Authority is weak, in respect of organization and man power, to protect illegal bilateral tariff application by counter part FTA countries. And therefore this study suggests the policy makers to arrange detailed FTA origin verification procedures with earliest meeting with counter part FTA countries, and further stress that make up of organization and man power for origin verification in a timely manner.