• Natural Product Sciences
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• 제26권3호
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• pp.221-229
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• 2020

This study was undertaken to investigate the protective effect of rice bran oil (RBO) on amyloid β protein (Aβ) (25-35)-induced memory impairment and brain damage in an ICR mouse model. Memory impairment was produced by intracerebroventricular microinjection of 15 nmol Aβ (25-35) and assessed using the passive avoidance test. Treatment with RBO at 0.1, 0.5, or 1 mL/kg (p.o. daily for 8 days) protected against Aβ (25-35)-induced memory impairment. Furthermore, Aβ (25-35)-induced decreases in glutathione and increases in lipid peroxidation and cholinesterase activity in brain tissue were inhibited by RBO, and Aβ (25-35)-induced increases of phosphorylated mitogen-activated protein kinases (MAPKs) and inflammatory factors, and changes in the levels of apoptosis-related proteins were significantly inhibited by RBO. Furthermore, Aβ (25-35) suppressed the PI3K/Akt pathway and the phosphorylation of CREB, but increased phosphorylation of tau (p-tau) in mice brain; these effects were significantly inhibited by administration of RBO. These results suggest that RBO inhibits Aβ (25-35)-induced memory impairment by inducing anti-apoptotic and anti-inflammatory effects, promoting PI3K/Akt/CREB signaling, and thus, inhibiting p-tau formation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1027-1028
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• 2008

Most of the urban transit operation company in Korea have a passive surveillance system to monitor the status of the passengers and facilities in the urban transit service area. The surveillance system is based on CCTV, closed circuit television, and several sensors, such as a fire sensor. However, this system has some limitations to prevent and cope with the emergency quickly. So the urban transit operation companies have plans to be change their surveillance system to be active. The active surveillance system has an intelligent function to detect the event predefined by managers automatically. To construct the active surveillance system, there are a standard concept design and a function analysis. In this paper, we propose the classification of the functions of the active surveillance system for urban transit. We divide the functions into five parts, ordinary monitoring, safety monitoring, environment monitoring, administration support, and record management. And we describe the systems related to the every functions to clarify the classified functions.

• Journal of Astronomy and Space Sciences
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• 제29권4호
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• pp.413-422
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• 2012

In recent years, a number of missions have been planned and conducted worldwide on the planets such as Mars, which involves the unmanned robotic exploration with the use of rover. The rover is an important system for unmanned planetary exploration, performing the locomotion and sample collection and analysis at the exploration target of the planetary surface designated by the operator. This study investigates the development of mobility system for the rover ground model necessary to the planetary surface exploration for the benefit of future planetary exploration mission in Korea. First, the requirements for the rover mobility system are summarized and a new mechanism is proposed for a stable performance on rough terrain which consists of the passive suspension system with 8 wheeled double 4-bar linkage (DFBL), followed by the performance evaluation for the mechanism of the mobility system based on the shape design and simulation. The proposed mobility system DFBL was compared with the Rocker-Bogie suspension system of US space agency National Aeronautics and Space Administration and 8 wheeled mobility system CRAB8 developed in Switzerland, using the simulation to demonstrate the superiority with respect to the stability of locomotion. On the basis of the simulation results, a general system configuration was proposed and designed for the rover manufacture.

• 인터넷정보학회논문지
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• 제19권1호
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• pp.113-122
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• 2018

In today's rapidly changing environment, companies need to have proper strategies in place to meet the challenges that constant change presents. Being flexible, responding and adapting to changes can be valuable. However, they are essentially passive ways of dealing with situations. Creating new values and innovation are more active and effective strategies fora constantly changing environment. As such, most companies in e-business should focus on developing creativity across the board. Employees' creativity has become a critical factor in e-business. This paper explains how to increase workers' creativity through authentic leadership and psychological empowerment. As it is not machines or computers, but people, that are ultimately still responsible for creating novel outcomes, this study emphasizes the overriding importance of members' ability and leader's roles, which greatly influence followers' levels of motivation. Authentic leadership encourages members to reach and display their potential, and enhances their intrinsic motivation. Moreover, members' psychological empowerment is directly associated with both intrinsic motivation and autonomy, preconditions for creativity. Hence, these two dimensions- leadership and an individual's psychological state- will increase workers' creativity, which works to increase performance and create more opportunities not only at the individual level, but also at the team or organization level. The purpose of this paper is to explain the effects of authentic leadership on creativity and the moderating effects of psychological empowerment between authentic leadership and creativity in the e-business environment.

• 한국항공운항학회지
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• 제21권4호
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• pp.112-118
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• 2013

Air travel demand has recently been growing and establishment and operation of low-cost carriers have been increased. Against this backdrop, low-cost carriers need to figure out diversified customer demand for low-cost carriers and ways to maximize marketing efficiency before applying it to the field so that they can attain superiority to large carriers in increased intensified competition. Low-cost carriers need to be differentiated from other carriers for the purpose of improving profits. Toward this end, this study conducted analysis on importance and satisfaction with carrier choice using IPA with regard to low-cost carrier customers. In conclusion, the paper accurately examined advantages and disadvantages of low-cost carriers compared to general carriers based on results of IPA analysis and suggested managerial strategies to enhance competitiveness based on division into four parts including maintenance and enforcement (1st quadrant, Delay compensation, Booking rapidity, Check rapidity, Crew service, refund service, baggage service, punctuality, transit services, airlines images), concentrated improvement (2nd quadrant, price, Convenience of seat), passive administration (3rd quadrant, Boarding service, cabin cleanliness, flight schedule, whether local crew on board, meal service, in-flight entertainment service), and enhanced satisfaction (4th quadrant, duty-free service, Variety of routes), so that practical suggestions could be presented to employees working in the field.

• 보건교육건강증진학회지
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• 제27권2호
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• pp.69-78
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• 2010

Objectives: The purpose of this study was to investigate the basic grounds for the policies of health promotion on the elderly by analyzing lifestyle. Methods: This study recruited 500 seniors aged over 65 years participating in exercise programs for the elderly provided by four branch offices of NHIC in Daegu. Results: 'Ideal type' was a group thinking that exercise programs for the elderly made their life healthy and energetic and living a happy life and 'social type' was a group answering that they helped to manage their health condition and to relieve stress and activated relationship with family members and friends to gain self-confidence. ‘Passive type’ and 'lethargic type’ said that the programs did not influence their life overall. Conclusion: Entrance into an aging society has changed values of the elderly. Their lifestyle becomes various and the effect of exercise programs for the elderly was also different according their lifestyle. Therefore, exercise programs considering lifestyles of the elderly will maximize their effect.

• 한방안이비인후피부과학회지
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• 제14권2호
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• pp.231-241
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• 2001

Mahwang-Shin-Gung-San has been found inhibiting the mast cell-mediated anaphylactic reaction. This report describes an inhibitory effect of Mahwang-Shin-Gung-San (MSGS) on the immediate-type cutaneous allergic reactions. MSGS has concentration -dependently inhibited the ear swelling response induced by compound 48/80 in mouse by intradermal injection. The mast cells in mouse ear tissue undergone ear-swelling response by compound 48/80 were stained by alcian blue/nuclear fast red. MSGS significantly inhibited the compound 48/80-induced degranulation from mast cells in ear tissue. MSGS concentration-dependently inhibited the histamine release from the rat peritoneal mast cells (RPMC) by compound 48/80. We also studied the effect of MSGS on mast cell-dependent passive cutaneous anaphylaxis (PCA) activated by dinitrophenyl IgE antibody. MSGS showed potent inhibition of PCA by oral administration. These results indicate that MSGS inhibits immediate-type allergic reactions by inhibition of mast cell degranulation in vivo and in vitro.

• Natural Product Sciences
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• 제16권2호
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• pp.93-98
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• 2010

The Chongmyung-tang (CMT) has been used as an oriental herbal medicine for the purpose of enhanced learning and memory. Recently, since fermentation may give a positive effect on pharmacological actions of herbal medicine, many studies are focused to find fermented medicinal herbs with improved bioactivity. In the present study, memory enhancing, antioxidant and reducing power activity of CMT and fermented CMT with Aspergillus oryzae (FCMT-A) or Saccharomyces cerevisiae (FCMT-S) were determined. To evaluate the memory enhancing activities of CMT, FCMT-A and FCMT-S, we performed passive avoidance test using scopolamine induced amnesia model. Administration of CMT, FCMT-A and FCMT-S showed a significant memory enhancing effect about 72.5, 78.3, 71.8% of the normal group respectively. CMT, FCMT-A and FCMT-S also exhibited strong $DPPH{\bullet}$, ${\bullet}{O_2}^-$, $NO^{\codt}$, $ABTS^{{\cdot}+}$ scavenging activities and reducing ower. It was also found that fermented CMT has slightly higher scavenging activities on $DPPH{\bullet}$, $ABTS^{{\cdot}+}$ radicals compared to CMT. These results revealed that CMT, FCMT-A and FCMT-S had memory enhancing and radical scavenging activities. In addition, the fermentation of CMT was more or less important for elevated memory enhancing and antioxidant activities of CMT.

• 한방안이비인후피부과학회지
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• 제15권2호
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• pp.33-52
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• 2002

The effects of Arctii fructus extract on allegenic inflammation were investigated using in vivo and in vitro test models. Firstly, the cytotoxicity of Arctii fructus extract was validated using MTT assay. As a result, Arctii fructus extract showed no cytotoxic potential, while SDS, a positive control, revealed strong cytotoxic effect. In LLNA assay, Arctii fructus extract showed no skin allergenicity. Next, the anti-allergic actions of Arctii fructus extract were evaluated using rodent experimental models. The oral, intraperitoneal and intradermal administration of Arctii fructus extract significantly inhibited the compound 48／80-induced vascular permeability documented by Evans blue extravasation. In addition, Arctii fructus extract showed potent inhibitory effect on passive cutaneous anaphylaxis activated by anti-dinitrophenyl (DNP) IgE when orally administered. In an in vitro study, Arctii fructus extract revealed to possess inhibitory potential on the compound 48／80-induced histamine release from rat peritoneal mast cells. Moreover, Arctii fructus extract inhibited the IL-4 and TNF-${\alpha}$ mRNA induction by PMA and A23187 in human leukemia mast cells, HMC-1. Finally, it revealed that Arctii fructus extract significantly suppressed histamin-provoked antigenic inflammation reactions in human prick test. Taken together, these results suggest that anti-allergic action of Arctii fructus extract may be due to the inhibition of histamine release and cytokine gene expression in the mast cells.

• 아태비즈니스연구
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• 제10권4호
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• pp.77-86
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• 2019

The purpose of this study is to examine how the characteristics of family firms affect stock price crash risk. Prior studies argued that the opacity of information due to agency problem causes a plunge in stock prices. The governance characteristics of family firms can increase information opacity which leads to crash risk. Therefore, this study verifies whether family firms have a high possibility of stock price crash risk. We use a logistic regression model to test the relationship between family firms and stock price crash risk using listed firms listed on the Korean Stock Exchange during the fiscal years 2011 through 2017. The family firm is defined as the case where the controlling shareholder is the chief executive officer or the registered executive. If the controlling shareholder's share is less than 5%, it is not considered a family business. We found that family firms are more likely to experience a plunge in stock prices. This supports the hypothesis of this study that passive information disclosure behavior and information opacity of family firms increase stock price crash risk.