• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.245-249
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• 2005

This paper describes a boost converter cascaded high frequency link direct dc-ac converter suitable for fuel cell power sources. A new multi-loop control for a boost converter to reduce the low frequency input current harmonics drawn from fuel cell is proposed. A new PWM technique for the cycloconverter at the secondary to reject the low order harmonics in the output voltages is presented in detail.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.11
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• pp.1424-1431
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• 2004

With traditional experimental methods such as the secondary fluid (e.g., water) calorimetric method, it is very difficult to accurately test the local condensation heat transfer inside mini-channels. Hence, there are large discrepancies between the results of previous studies. The experimental methods as well as unidentified sources of uncertainties could be reasons for such discrepancies. In this study, innovative experimental techniques were developed to measure the in-tube condensation heat transfer coefficient. With these techniques, very low heat dissipation rates such as several watts from the mini-channel could be estimated and low mass flow rates below the 0.1 ㎏/h could be measured with reasonable uncertainties. To the authors' knowledge, these techniques provide a unique experimental apparatus for measuring the condensation heat transfer coefficients inside the sub-millimeter hydraulic diameter single channels.

• Journal of Smart Tourism
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• v.1 no.2
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• pp.13-18
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• 2021

Hotels have recently started to implement enterprise information systems to measure and report sustainability indicators in a smart manner. However, a complex ownership structure in a hotel chain prevents full smart systems adoption at the individual property level. This study explores how a smart sustainability performance measurement system (SPMS) for waste management adoption correlates with customer ratings, customer reviews, operational efficiency scores, and between franchised and corporate-managed properties. We derive insights from the secondary data constructed from multiple sources for a large multinational hotel chain hotel. The findings suggest that hotels that adopt SPMS have better operational efficiency scores and more customer reviews. Within the hotels that adopted SPMS, corporate-managed hotels have a lower level of ratings than franchised hotels, but they have higher operational efficiency scores and more reviews. We discuss research implications for the concept of smart tourism and hotel management literature and managerial implications.

• The Transactions of the Korean Institute of Power Electronics
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• v.25 no.6
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• pp.425-432
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• 2020

The phase-shifted, full-bridge (PSFB) DC-DC converter is widely used in electric vehicles (EVs) to charge a low-voltage (12 V) battery from a high-voltage battery. A Photovoltaic (PV) module-integrated PSFB converter is proposed for the EV power conversion system. The converter is useful because solar energy can be utilized to extend the driving range. The buck converter circuit is simply realized by adding one switch to the conventional PSFB converter's secondary side. For the inductor and diode, the existing components in the PSFB converter are shared. The proposed converter can charge a low-voltage battery from the PV module with maximum power point tracking. In addition, the two power sources can be used simultaneously, and efficiency is increased by reducing the circulating current, which is a problem for the conventional PSFB converter.

• Natural Product Sciences
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• v.28 no.3
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• pp.93-104
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• 2022

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious threat to the global healthcare system. Ineffective and resistance to antibiotic treatments have increased morbidity and mortality rates worldwide. New and effective antibiotics are needed to combat against bacterial resistance. Endophytic fungi are crucial reservoirs of novel bioactive metabolites. In particular, the secondary metabolites show promising therapeutic potential, notably, antibacterial. This review discussed the emerging potential of endophytic fungi as anti-MRSA agents. The ecological sources of endophytic fungi were discussed with the synthesis of bioactive metabolites. The mode of antibacterial actions was elucidated to give a better understanding of the mechanisms involved. This review may serve as an important reference for future discovery and developments of anti-MRSA agents from endophytic fungi.

• International conference on construction engineering and project management
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• 2007.03a
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• pp.593-600
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• 2007

This paper presents the preliminary observations of an ongoing study that is looking into organisational changes that are externally imposed using the institutional theory. The study population are the government-linked companies involved in housing development (GLCHD) in Malaysia. For the purpose of this paper, only two are highlighted. From secondary sources, elements of changes that have exerted on these two GLCHD over the last six years and the internal changes that have taken place during the same time period were identified. The tentative conclusion is that external environment contributed to organisational change in the two GLCHD.

• Asia Marketing Journal
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• v.18 no.1
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• pp.1-22
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• 2016

Studies in key account management (KAM) have identified the importance of cross-functional coordination in firms to effectively implement KAM. However, these studies have ignored how companies integrate KAM and other customer management (non-KAM). This paper explores coordination design between KAM units and non-KAM units by analyzing a case study through three dimensions: front-end coordination, back-end-coordination, and organizational translation at the beginning of research. The case study shows that non-KAM conditions can require a modification of the coordination design. This research performs an in-depth analysis of changes in the implementation of sales reforms for an IT-related machinery and system vendor in Japan. Data sources include interviews with KAM units and non-KAM sales units and an analysis of secondary data. This paper suggests that studying the coordination between KAM units and non-KAM units will further our understanding of internal coordination in KAM research.

• The Korean Journal of Franchise Management
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• v.7 no.1
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• pp.5-11
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• 2016

Purpose - The purpose of this paper is to find the issues associated with international expansion of Korean franchisors going international and suggest lessons of proposition to reduce the failure risk in international expansion of franchise systems. Research design, data, and methodology - This is the exploratory study and structured to review (1) background to motivate the expansion of franchisors towards international market, (2) the status of Korean franchisors going international in recent years, (3) issues, (4) lessons learned from the experiences, and (5) summary. Secondary sources were reviewed to get necessary data and statistics. Results - Master franchising was the most preferred entry mode for Korean franchisors. Franchisors must understand the expenses to be incurred as well as revenues associated with international activities. Brand is the core asset of franchisor as a differentiation strategy. Conclusions - The paper indicates that even if international franchising is the unique business model for franchisors to use in little or least risk compared with other international entry modes, it needs a set of complex capabilities that much differ from those in domestic and franchisors should take a step approach to the international market with the planned and long term perspective.

• Mycobiology
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• v.51 no.6
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• pp.410-416
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• 2023

Fungi are cosmopolitan and they occupy diverse niches as consumers, producers, and decomposers. They play critical roles in the environment by enabling nutrient cycling and generating a plethora of secondary metabolites. This study aimed to identify and characterize fungal strains isolated from diverse sources on Muui Island, Republic of Korea. In 2023, a total of 86 fungal strains were collected and examined. Investigation of the morphological features and phylogenetic analyses of multiple barcode loci identified one putative novel species and two species previously unrecorded in the Republic of Korea: Colletotrichum sp., Colletotrichum guizhouense, and Fusarium brachygibbosum. This study provides a comprehensive description of their molecular phylogenies and morphological characteristics. These findings will contribute to the existing knowledge about fungal species in the Republic of Korea and future research on the fungal diversity on Muui Island.

• Economic and Environmental Geology
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• v.36 no.5
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• pp.365-374
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• 2003

Various deleterious chemicals can be introduced to existing concrete structures from various external sources. The deterioration of concrete by seawater attack is involved in complex processes due to various elements contained in seawater. In the present study, attention was paid to the formation of secondary minerals and characteristics of mineralogical and micro-structural changes involved in concrete deterioration caused by the influence of major seawater composition. The characteristics of deterioration occurred in existing concrete structures was carefully observed and samples were collected at many locations of coastal areas in Busan-Kyungnam. The petrographic, XRD, SEM/EDAX analyses were conducted to determine chemical, mineralogical and micro-structural changes in the aggregate and cement paste of samples. The experimental concrete deteriorations were performed using various chloride solutions (NaCl, CaCl, $MgCl_2$ and $Na_2SO_4$ solution. The experimental results were compared with the observation results in order to determine the effect of major elements in seawater on the deterioration. The alkalies in seawater appear to accelerate alkali-silica reaction (ASR). The gel formed by ASR is alkali-calcium-silica gel which known to cause severe expansion and cracking in concrete. Carbonation causes the formation of abundant less-cementitious calcite and weaken the cement paste. Progressive carbonation significantly affects on the composition and stability of some secondary minerals. Abundant gypsum generally occurs in concretes subjected to significant carbonation, but thaumasite ({$Ca_6/[Si(OH)_6]_2{\cdot}24H_2O$}${\cdot}[(SO_4)_2]{\cdot}[(CO_3))2]$) occurs as ettringite-thaumasite solid solution in concretes subjected to less significant carbonation. Experimentally, ettringite can be transformed to trichloroaluminate or decomposed by chloride ingress under controlled pH conditions. Mg ions in seawater cause cement paste deterioration by forming non-cementitious brucite and magnesium silicate hydrate (MSH).