• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2006.06b
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• pp.245-250
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• 2006

This study was focused on the use of cationic PAM (Polyacrylamide) as a surface sizing additive to improve the surface sizing properties of paper. Effects of the ionic property, viscosity and charge density of PAM on bending stiffness of surface sized papers were investigated. Use of cationic PAM as a surface sizing additive improved bending stiffness while addition of anionic PAM did not show any effect. Increase of starch holdout with the addition of cationic PAM was attributed as a prime reason of stiffness increase. Viscosity of PAM was one of the most important factors affecting surface sizing due to its influence on the interaction between cationic PAM and oxidized starch solution. Greater improvement of bending stiffness of paper was obtained when high charged PAM was used as an additive. The order of addition was found to have significant influence on the effect of additives since it influences the formation of network structure among starch, cationic PAM, and SA (styrene acrylic acid copolymer). Investigation on the penetration of starch solution was carried out with CLSM (Confocal Laser Scanning Microscopy), and it was shown that the addition of cationic PAM to oxidized starch solution made starch molecules stay on the paper surface rather than penetrating into the paper structure because of the electrostatic interaction between negatively charged fibers and positively charged cationic PAM.

• Safety and Health at Work
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• v.3 no.2
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• pp.104-109
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• 2012

Singapore, an island republic of over 5 million inhabitants, has 3.1 million workers. Most are employed in the service, finance and tourist/transport industry. Significant numbers work in manufacturing, construction and heavy industry. Following a series of construction and shipyard accidents with multiple deaths in 2004, the government announced its intention to reduce workplace fatalities from 4.9 to 2.5 per 100,000 by 2015. There was strong political will to achieve this target. The strategic approaches were to build workplace safety and health (WSH) capabilities; implement legislative changes with enforcement; promote benefits of WSH and recognize best practices, and enhance partnership with stakeholders. The anticipated outcomes were to reduce workplace fatality and injury rates; have WSH as an integral part of business; and establish a progressive and pervasive WSH culture. With these measures, the workplace fatality rate declined from 4.9/100,000 in 2004, to 2.2/100,000 in 2010. However, other confounding factors could also account for this decline, and have to be considered. The next target, announced by Singapore's Prime Minister in 2008, is to further reduce the workplace fatality rate to 1.8/100,000 by 2018, and to have "one of the best workplace safety records in the world".

• Journal of Astronomy and Space Sciences
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• v.35 no.1
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• pp.47-54
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• 2018

Moon mineralogy mapper ($M^3$)'s work proved that the moon is not completely dry but has some hydroxyl/water. $M^{3{\prime}}s$ data confirmed that the amount of hydroxyl on the lunar surface is inversely related to the measured signal brightness, suggesting the lunar surface is sensitive to temperature by solar insolation. We tested the effect of solar insolation on the local distribution of hydroxyl by using $M^3$ data, and we found that most craters had more hydroxyl in shade areas than in sunlit areas. This means that the local distribution of hydroxyl is absolutely influenced by the amount of sunshine. We investigated the factors affecting differences in hydroxyl; we found that the higher the latitude, the larger the difference during daytime. We also measured the pyroxene content and found that pyroxene affects the amount of hydroxyl, but it does not affect the difference in hydroxyl between sunlit and shaded areas. Therefore, we confirmed that solar insolation plays a significant role in the local distribution of hydroxyl, regardless of surface composition.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.69-87
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• 2002

Implant material, implant design, surface quality, status of the bone, surgical technique, and implant loading conditions were regarded as prerequisites for osseointegration which is a prime condition for implant success. The aim of this review paper was to investigate the survival rate of single implants in relation to the prerequisites for osseointegration. Fifty-eight papers reporting survival rates of single implants were selected by use of the 'PubMed' and hand searching. The survival rate of single implants were assessed with reference to factors influencing osseointegration. The results showed that single implants in general showed a high survival rate except a few failures in certain extreme conditions and early stages. Those failures and complications such as screw loosening and esthetic problem were almost solved with the development of implant components and surgical techniques and a better understanding of biology around a single implant. Single-tooth implant-replacement is now considered as a reliable and predictable treatment option for a single missing tooth and its application seems to expand to compromised situations which were previously thought to be impossible for single implant therapy.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.1
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• pp.59-70
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• 2010

This paper reorganized five service qualities dimensions of ski-resorts, then derived the improvement priority order of the service quality through a satisfaction measure considering the importance. There're more competitive situations to guarantee customers using the skies and snowboards is a major sports in winter season. In these competitive environments, this paper's going to propose a predominant-competitive strategies for improving the service quality of ski-resorts. This study measured the satisfaction considering the importance of service quality target on customers has an experience ski resort service quality to improve ski resort service quality. This study using Performance Model decide a priority order about a particular item improvement, then is going to present a guideline that can improve the service quality more exactly. As a result of the study the factors that is important to the customer were prime physical factor, access, assistance physical factor, staff service and assistant service, an improvement priority order were accommodation and eating-drinking facilities, waiting time of a slope and lift/gondola, entertainment/shopping facilities in the resorts, equipment rental and lift fare.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.4
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• pp.737-744
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• 2018

The RSA cryptosystem is a one of the first public-key cryptosystems and is widely used for secure data transmission and electric signature. The security of the RSA cryptosystem is based on the difficulty of factoring large numbers.. Though many studies on finding methods for factoring large numbers are going on, the results of that are all experimental or probabilistic. We, in this paper, construct an algorithm for finding large prime factors of integers without factoring integers using properties of the structure of semigroup of imaginary quadratic order and non-invertible ideal, then propose our methods foe deterministic attack against RSA cryptosystem.

• Environmental Mutagens and Carcinogens
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• v.26 no.4
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• pp.97-112
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• 2006

Heme oxygenase(HO)-1 is an important antioxidant enzyme that plays a pivotal role in cellular adaptation and protection in response to a wide array of noxious stimuli. Thus, HO-1 induction has been associated with prevention or mitigation of pathogenesis of various diseases, including acute inflammation, atherosclerosis, degenerative diseases, and carcinogenesis. Recent progress in our understanding of the function of molecules in the cellular signaling network as key modulators of gene transcription sheds light on the molecular mechanisms underlyuing HO-1 gene expression. A panel of redox-sensitive transcription factors such as activator protein-1, nuclear factor-kB, and nuclear factor E2-related factor-2, and some of the upstream kinases have been identified as prime regulators of HO-1 gene induction. This review summarizes molecular mechanisms underlying HO-1 expression and the significance of targeted induction of HO-1 as a potential chemopreventive or chemoprotective strategy.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.41 no.8
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• pp.545-552
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• 2017

In this research, numerical analysis was carried out on novel and existing fins, adjusted in terms of factors such as length, spacing, and angle, of a high-temperature heat exchanger for a 1 kW class Stirling engine, designed as a prime mover for a domestic cogeneration system. The performance improvement as a result of shape optimization was confirmed with numerical analysis by including the air preheater, which was not considered during optimization. However, a negative heat flux was observed in the cylinder head portion. This phenomenon was clarified by analyzing the exhaust gas and wall surface temperature of the combustion chamber. Furthermore, assuming an ideal cycle, the effects of heat transfer enhancement on the thermodynamic cycle and system performance were predicted.

• Proceedings of the KSPS conference
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• 2005.11a
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• pp.73-77
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• 2005

The purpose of this study is to observe how Korean learners of English perceive a weak syllable in words with WS syllable pattern. According to the automated discrimination task using E-Prime, the proportion of right answer and reaction time of the stimuli with same word pairs (a-a, b-b) was more and faster respectively than that with different word pairs (a-b, b-a). Specifically, in a-b or b-a stimuli structure, familiarity(word frequency) of stressed word succeeding weak syllable and whether the weak syllable had coda in it was two important factors in distinguishing between a word with and without weak syllable. Even though the high English proficiency Koreans had faster reaction time than the low English proficiency Koreans, all Korean learners somewhat had difficulty perceiving the weak syllable at the beginning of the word.

• Land and Housing Review
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• v.4 no.3
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• pp.211-223
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• 2013

Massive migration is underway in rapidly urbanizing Guangzhou, the south gate of P. R. China. Over half the migrants choose to rent in "villages-in-the-city" in the downtown area because of the low-cost and prime location. The overpopulation and resulting poor environment and high crime-rate turn villages-in-the-city into de facto ghettos. As a result, these ghettos are undergoing a manner of demolition-development, leaving migrants' housing needs unmet. A private-sector initiative-the Tulou Commune-intends to address this considerable market potential. Targeting low-income groups, the Tulou Commune creates a socio-spatially exclusionary enclave. This paper analyzes the Tulou Commune and the implications if more low-income migrants shifting from village-in-the-city (excluded ghetto) to Tulou Commune (exclusionary enclave). This study argues that the intervention of the private sector causes the demographic, social, and spatial similarities and differences of the two living arrangements. Socioeconomic and institutional factors also affect the initiative. This study also provides more empirical evidence in the field of low-cost housing and socio-spatial development in transitional Chinese cities. As the first project of its kind, the analysis of the case can suggest how to improve strategies for accommodating migrants in the future.