• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권9호
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• pp.3693-3711
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• 2020

e-Governance is a medium to offer various services to citizens through a web portal, that exists in many countries nowadays. The existing e-Governance technology is a vast, centrally managed database and a set of applications that connect to it via web interfaces. Despite the modernisation of services, it remains with the lack of transparency. Thus, the existing infrastructure of e-Governance paves the way for corrupt practises by the bureaucrats. e-Governance needs a powerful underlying technology which doesn't provide any way to allow tampering of the record and which in turn eliminates corruption. In this paper, we took land registration as a use-case for building e-Governance by keeping Blockchain as an underlying technology, to put off the corrupt practices and to bring transparency. Once transactions in land registration added to the Blockchain, it is immutable as it is cryptographically secured. Besides, the blockchain technology is secured as the ledger is distributed over the network. If a hacker wants to modify the ledger, he needs to hack every node in the blockchain network. Hyperledger Fabric, a permissioned Blockchain adopted for implementation and Hyperledger Caliper for performance analysis with these evaluation metrics such as throughput, latency and execution time.

• 국제초고층학회논문집
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• 제4권4호
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• pp.283-290
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• 2015

Crack control remains a primary concern for mass concrete structures, where the majority of cracking is caused by temperature changes during the hydration process. One-time pouring is a useful construction method for mass concrete structures. The suitability of this method for constructingon of the Shanghai Tower's mass concrete foundation slab of Shanghai Tower is considered here by a numerical simulation method based on a 6- meter- thick slab. Some of the conclusions, which can be verified by monitoring results conducted during construction, are as follows. The temperature gradient is greater in the vertical direction than in the radial direction, therefore, the vertical temperature gradient should be carefully considered for the purpose of crack control. Moreover, owing to cooling conditions at the surfaces and the cement mortar content of the slab, the temperatures and temperature gradients with respect to time vary according to the position within the slab.

• 농업과학연구
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• 제33권1호
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• pp.43-56
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• 2006

In this thesis we aim at analyzing international competitive power of Chinese ginseng in comparison with Korean ginseng and searching policy direction for Korea to compete Chinese ginseng industry. We summarized the research results as follows; First, we examine the structural change of ginseng industry of China. Second, we review the theories for international competitiveness and apply the method of analyzing competitiveness to ginseng industry. Third, we compared the international competitive power of the ginseng industry between China and Korea and found that Chinese ginseng, estimated by Revealed Comparative Advantage(RCA) at about 15, still remains high competitiveness in terms of cost and price but lowering price competitiveness recently. Based on the research results, we suggest export promotion strategies of the Korean ginseng as follows; 1) Korean government should enforce trade cooperation with China so as to register Korean root ginseng an importable medicine. 2) Korean ginseng producer should develop various products such as capsules, powders and etc. according to China's consumer purchasing power and taste. 3) Korean ginseng should be sold as an differentiated commodity so that it will contribute to building consumer loyalty to Korean ginseng, makes market share superior to other cheaper ginseng products in China. 4) In order to be effective brand marketing and product advertisement, there should be established reliable networks to process and distribute Korean ginseng products exclusively.

• 천문학회지
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• 제34권1호
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• pp.25-29
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• 2001

We have constructed a non-spherical model for the hot oxygen corona of Mars by including the effects of planetary rotation and diurnal variation of the Martian ionosphere. Exospheric oxygen densities are calculated by integrating ensemble of ballistic and escaping oxygen atoms from the exobase over the entire planet. The hot oxygen atoms are produced by dissociative recombination of $O^+_2$, the major ion in the Martian ionosphere. The densities of hot oxygen atoms at the exobase are estimated from electron densities which have been measured to vary with solar zenith angle. Our model shows that the density difference of hot oxygen atoms between noon and terminator is about two orders of magnitude near the exobase, but reduces abruptly around altitudes of 2000 km due to lateral transport. The diurnal variation of hot oxygen densities remains significant up to the altitude of 10000 km. The diurnal variation of the hot oxygen corona should thus be considered when the upcoming Nozomi measurements are analyzed. The non-spherical model of the hot oxy-gen corona may contribute to building sophisticate solar wind interaction models and thus result in more accurate escaping rate of oxygens from Mars.

• Industrial Engineering and Management Systems
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• 제16권1호
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• pp.80-91
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• 2017

Multiple prior studies stress that continued Kaizen activity is conducive to building and maintaining competitive advantages of manufacturing companies. Meanwhile, it remains unclear as to what kind of management factors may exert impact on sustainment of Kaizen activity. This paper discusses a study conducted on the cases of two manufacturing lines, where such activity has been continued for more than ten years. At first, it was discovered that study period was divided into different periods. It was also found out that 'standstill conditions' which prevent smooth progress of activity exist in many periods, and that such conditions are hard to avoid. The study went on to categorize progress of activity in each period into different patterns, including at which points standstill conditions occurred, thereby, circumstances of standstill conditions were made clear. This paper verified a detailed process of Kaizen activity development in each period and the relationship between that detailed process and points of occurrence of standstill conditions. Thought was also given to factors and actions for smooth development, and effects brought about by overcoming such challenges. Lastly, consideration was given to the future perspectives of the study for elucidating how better Kaizen activity may be managed for continuation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권10호
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• pp.3607-3623
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• 2014

The increasing demand in promoting cloud computing in either business or other areas requires more security of a cloud storage system. Traditional cloud storage systems fail to protect data integrity information (DII), when the interactive messages between the client and the data storage server are sniffed. To protect DII and support public verifiability, we propose a data integrity verification scheme by deploying a designated confirmer signature DCS as a building block. The DCS scheme strikes the balance between public verifiable signatures and zero-knowledge proofs which can address disputes between the cloud storage server and any user, whoever acting as a malicious player during the two-round verification. In addition, our verification scheme remains blockless and stateless, which is important in conducting a secure and efficient cryptosystem. We perform security analysis and performance evaluation on our scheme, and compared with the existing schemes, the results show that our scheme is more secure and efficient.

• 보존과학회지
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• 제35권4호
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• pp.373-383
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• 2019

We characterized the smelting process and smelting furnace through scanning electron microscopy-energy dispersive spectroscopy, wavelength dispersive X-ray fluorescence, X-ray diffraction, and raman micro-spectroscopy with 13 relics including slags and furnace walls excavated from square-shaped building sites and pits of the Three Kingdoms site at the Ungyo site section I. Our results revealed that the principal components were FeO and SiO₂; and CuO, PbO, and ZnO were contained in small quantities. Furthermore, fayalite, magnetite, augite, copper, and cuprite were found. High contents of FeO or SiO₂ components seem to have been added to form fayalite to remove gangue in the smelting process. The relatively low content of S detected in the copper prills suggests that roasting was performed well. Cristobalite and mullite, which are minerals that indicate high-temperature found in the furnace wall, show that the smelting temperature was higher than 1,250℃. The findings of this study show a high possibility that the Wanju Ungyo site is smelting remains of copper ores, which are nonferrous metals, rather than iron. Various smelting byproducts excavated in this area in the future will help us better understand the copper smelting process that may have been performed since ancient times.

• 한국산학기술학회논문지
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• 제9권4호
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• pp.1012-1017
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• 2008

최근 무선통신 기술의 발달과 편리성으로 무선 랜의 활용 증가하고 있다. 이와 더불어 무선랜의 보안 위협과 취약성에 대하여 이슈화 되고 있다. 따라서 IEEE에서는 802.11 표준안을 제정하고 무선 랜의 보안 취약점을 보완 하기 위해 802.11i등 새로운 표준들을 제정하고 있지만, 아직까지 해결되지 않은 보안 위협들이 존재한다. 본 논문에서는 액세스 포인트의 비콘 프레임을 이용하여 건물 내 액세스 포인트의 보안 상태 와 비인가 액세스 포인트를 탐지하는 시스템과 RSSI, 삼각측량범 및 칼만필터 알고리즘을 사용한 위치탐지 알고리즘을 제안하고, 기존 탐지 알고리즘과 제안 알고리즘의 결과 비교로 성능을 평가하였다.

• Structural Engineering and Mechanics
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• 제20권5호
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• pp.589-608
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• 2005

There is a growing need for the development and implementation of new methods for the rapid and cost-effective rehabilitation of deteriorating steel structural components to offset the drawbacks related to welding and/or bolting in the field. Carbon fiber reinforced polymer (CFRP) composites provide a potential alternative as externally bonded patches for strengthening and repair of metallic structural members for building and bridge systems. This paper describes results of an investigation of tensile and fatigue response of steel/CFRP joints simulating scenarios of strengthening and crack-patching. It is shown that appropriately designed schemes, even when fabricated with levels of inaccuracy as could be expected in the field, can provide significant strain relief and load transfer capability. A simplified elasto-plastic closed form solution for stress analysis is presented, and validated experimentally. It is shown that the bond development length remains constant in the linear range, whereas it increases as the adhesive is deformed plastically. Fatigue resistance is shown to be at least comparable with the requirements for welded cover plates without attendant decreases in stiffness and strength.

• 대한방사성의약품학회지
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• 제4권1호
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• pp.16-21
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• 2018

Organoboron compounds and their derivatives are synthetically versatile building blocks because they are readily available, stable, and highly useful for potential organic transformations. Arylboronic esters are of particular interest due to their well-established synthetic methods: transition metal catalyzed borylations of aryl halides. However, the use of aryl halides as an electrophile has one serious disadvantage: formation of toxic halogenated byproducts. A promising alternative substrate to aryl halides would be phenol derivatives such as aryl ethers, esters, carbamates and sulfonates. The phenol derivatives involve several advantages: their abundance, relatively low toxicity and versatile synthetic application. However, utilization of the aryl methyl ether, which is one of the simplest phenol derivatives, remains as a challenge, as C-OMe bond activation requires high activation energy and methoxides are not good leaving groups. Nevertheless, there have been a significant recent progress on ipso-borylation of aryl methyl ether including Martin's nickel catalysis. Here, we review the current advance on the borylation of carbon-oxygen bonds of unactivated C-OMe bond in aromatic compounds.