• Proceedings of the KSR Conference
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• 1999.11a
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• pp.318-325
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• 1999

Modern AC electric car has PWM(Pulse Width Modulation)-controlled converters, which give rise to higher harmonics. The current harmonics injected from AC electric car is propagated through power feeding circuit, As the feeding circuit is a distributed constant circuit composed of RLC, the capacitance of the feeding circuit and the inductance on the side of power system cause a parallel resonance and a magnification of current harmonics at a specific frequency. The magnified current harmonics usually brings about various problems. That is, the current harmonics makes interference in the adjacent lines of communications and the railway signalling system. Furthermore, in case it flows on the side of power system, not only overheating and vibration at the power capacitors but also wrong operation at the protective devices can occur. Therefore, the exact assessment of the harmonic current flow must be undertaken at design and planning stage for the electric traction systems. From these point of view, this study presents an approach to model and to analyse traction power feeding system focused on the amplification of harmonic current The proposed algorithm is applied to a standard AT(Auto-transformer)-fed test system in which electric car with PWM-controlled converters is running.

• Korean Journal of Medicinal Crop Science
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• v.27 no.3
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• pp.186-193
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• 2019

Background: Astringent persimmon (Diospyros kaki Thunb. cv. Kojongsi) peels are by-products of dried persimmons. This study aimed to evaluate the antioxidant activities of Kojongsi persimmon peel (KPP) extracts prepared by 15 different extraction methods: 5 heating durations (0.5 - 2.5 h) at 3 heating temperatures (50, 70, and $90^{\circ}C$). Methods and Results: An increase in heating temperature increased the antioxidant effect of KPP extracts. Those prepared by heating at 1 h had the highest total phenol content, regardless of the heating temperature. In addition, the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and cell-protective effects against $H_2O_2-induced$ oxidative stress were dependent on the total phenol contents of the extract. However, the KPP-induced increased in catalase expression was dependent on heating temperature and duration. Conclusions: These results suggest that extraction by heating at $90^{\circ}C$ for 1 h may enhance KPP's antioxidant effects, which mainly involve non-enzymatic antioxidant systems.

• Journal of the Korea Fashion and Costume Design Association
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• v.23 no.2
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• pp.93-104
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• 2021

The worldwide coronavirus pandemic has brought to light the importance of having a reliable supply of masks for each person. This study aims to understand the effect of personal awareness (including community, others', and safety awareness) on consumption conformity and the repurchase intention of masks. The research method used the SPSS 22.0 and AMOS 22.0 statistical systems to analyze descriptive statistics in terms of reliability, validity, structural equation modeling, and moderated regression analysis. A total of 272 Chinese participants were recruited via an online survey website (www.sojump.com) from May 1 to May 14, 2020. Findings indicated that mask users' awareness can be categorized into three distinct types: community, others', and safety awareness. The more community and safety awareness is perceived, the higher the level of consumption conformity. In contrast, others' has no statistical effect on consumption conformity or repurchase intention. The positive influence of consumption conformity on the repurchase intention of masks is also weaker than price perception. However, another moderating variable, mask quality, has no moderating effect. The results of this study can help mask manufacturers and distributors retain their customers, resulting in reasonable protective measures while maintaining market order. Theoretical and managerial implications for mask suppliers are also provided.

• Parasites, Hosts and Diseases
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• v.60 no.6
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• pp.379-391
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• 2022

Leishmaniasis is a serious parasitic disease caused by Leishmania spp. transmitted through sandfly bites. This disease is a major public health concern worldwide. It can occur in 3 different clinical forms: cutaneous, mucocutaneous, and visceral leishmaniasis (CL, MCL, and VL, respectively), caused by different Leishmania spp. Currently, licensed vaccines are unavailable for the treatment of human leishmaniasis. The treatment and prevention of this disease rely mainly on chemotherapeutics, which are highly toxic and have an increasing resistance problem. The development of a safe, effective, and affordable vaccine for all forms of vector-borne disease is urgently needed to block transmission of the parasite between the host and vector. Immunological mechanisms in the pathogenesis of leishmaniasis are complex. IL-12-driven Th1-type immune response plays a crucial role in host protection. The essential purpose of vaccination is to establish a protective immune response. To date, numerous vaccine studies have been conducted using live/attenuated/killed parasites, fractionated parasites, subunits, recombinant or DNA technology, delivery systems, and chimeric peptides. Most of these studies were limited to animals. In addition, standardization has not been achieved in these studies due to the differences in the virulence dynamics of the Leishmania spp. and the feasibility of the adjuvants. More studies are needed to develop a safe and effective vaccine, which is the most promising approach against Leishmania infection.

• Journal of Korean Academy of Nursing
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• v.53 no.6
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• pp.584-596
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• 2023

Purpose: This study aimed to explore the perspectives of frontline nurses working during the novel coronavirus disease 2019 (COVID-19) pandemic. Methods: An online qualitative study was conducted using a pragmatic approach. The data were collected in August 2021. Registered Korean nurses who provided direct nursing care to patients with confirmed COVID-19 were eligible for this study. An online survey was used to gather free-text data, which were then analyzed using machine-based network analysis and summative content analysis. Results: The analysis examined the responses of 126 participants and led to the identification of six prominent themes. These themes were further classified into three distinct levels: personal, task, and organizational. The identified themes are as follows: "collapse of personal life," "being overwhelmed by the numerous roles required," "personal protective equipment was sufficiently provided, but that is not enough," "changes in interprofessional collaboration," "inappropriate workforce management," and "diverted allocation of healthcare services and resources." Conclusion: Our findings highlight areas for improvement in resources, systems, and policies to enhance preparedness for future pandemics.

• IMMUNE NETWORK
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• v.20 no.4
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• pp.35.1-35.13
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• 2020

Antigen delivery systems play critical roles in determining the quality and quantity of Ab responses in vivo. Induction of protective antibodies by B cells is essential in the development of vaccines against infectious pathogens, whereas production of IgE antibodies is prerequisite for investigation of allergic responses, or type 1 hypersensitivity reactions. Virus-like particles (VLPs) are efficient platforms for expression of proteins of interest in highly repetitive manners, which grants strong Ab responses to target antigens. Here, we report that delivery of hen egg lysozyme (HEL), a model allergen, through VLP could provoke strong HEL specific IgE Ab responses in mice. Moreover, acute allergic responses were robustly induced in the mice sensitized with VLPs that express HEL, when challenged with recombinant HEL protein. Our data show that antigen delivery in the context of VLPs could function as a platform for sensitization of mice and for subsequent examination of allergic reactions to molecules of interest.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.5
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• pp.537-547
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• 2014

The object of this study was to observe the effect of Banhasasim-tang (BHSST) on the HCl/EtOH-induced gastric ulcer in mice. Three different dosages of BHSST extract (400, 200 and 100 mg/kg) were once orally administered 1 hr before HCl/EtOH mixture treatment. One hour after HCl/EtOH mixture single oral treatment, the changes on the gross hemorrhagic lesion scores, fundic histopathology, gastric nitrate/nitrite contents, lipid peroxidation and antioxidant defense system (catalase and superoxide dismutase (SOD) activities) were observed, and compared with that of ranitidine 100 mg/kg. As results of all three different dosages of BHSST extract treatment in the HCl/EtOH-induced gastric ulcer mice, significant and dose-dependent decreased gastric damages. BHSST extracts also increased gastric nitrate/nitrite contents and strengthened the antioxidant defense systems, and increased the activities of catalase and SOD, respectively. BHSST extracts 200 mg/kg showed similar anti-ulcerative effect as compared with ranitidine 100 mg/kg, in this experiment. BHSST has favorable protective effects against to the HCl/EtOH-induced gastric damages, through the strengthening of the body antioxidant defense systems. These gastroprotective effects of BHSST against HCl/EtOH-induced gastric ulcer considered as results of complicated synergic effects of their 8 kinds of herbal components, but exact synergic or individual herbal effects are difficult to discuss in this study. Therefore, more detail synergic effects between 8 kinds of individual herbal component of BHSST should be tested with screening of active anti-inflammatory chemical ingredients, in future.

• Clinical and Experimental Pediatrics
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• v.52 no.11
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• pp.1185-1193
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• 2009

An act of children's welfare was made in 1961 for the first time in Korea but it had been nothing but the name in view of practical impact to prevention of child abuse. Real undertakings of Child Abuse Prevention were commenced overtly since 2000 in Korea, when the law for children's welfare was revised to put protective settings for the victims and to establish criterion for children's safety. The history of Child Abuse Prevention is very short in Korea but the reporting cases increased very fast from 4,133 cases in 2001 up to 9,570 cases in 2008 with the enthusiastic activities from people of the associated organizations along with the national supports. But the portion reported by the mandated reporters such as teachers or doctors is still low compared to those of the developed countries. The National Child Protection Agency (NCPA) was founded in 2001 by the Ministry of Health and Welfare to prevent child abuse and to aid recovery of abused and neglected children including their families, through the cooperation of related organizations. NCPA refers reported cases of child abuse to appropriate local centers, operates a computer database system for case management, publicizes national reports of child abuse on a yearly basis and technically supports the Local Child Protection Agency (LCPA) by developing scales for assessment of child abuse and neglect and distributing programs for the education of mandatory reporters. LCPAs operate 24-hour telephone hotline, investigate and visit homes and provide in home services networking with local resources, and operate multidisciplinary teams for screening child abuse victims and supervising case management through multimodal systems. We summarized the present state of child abuse in Korea and reviewed the operating systems for child protection in this country. Through this article, we hope that medical peoples are to be informed on the seriousness of child abuse and to be able to devote themselves for the prevention of child abuse.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.9
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• pp.1332-1339
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• 2017

Objective: This study investigated the effects of Bacillus subtilis CSL2 (B. subtilis CSL2) administration before Salmonella challenge on the fecal microbiota and microbial functionality of Hy-line Brown (HLB) laying hens. Methods: Fecal samples were collected from control (CON), Salmonella-infected (SAL) and Salmonella-infected, probiotic-treated (PRO) groups before and after Salmonella challenge for microbiome analysis using 16S rRNA gene pyrosequencing. Results: Infection with Salmonella led to decreased microbial diversity in hen feces; diversity was recovered with Bacillus administration. In addition, Salmonella infection triggered significant alterations in the composition of the fecal microbiota. The abundance of the phylum Firmicutes decreased while that of Proteobacteria, which includes a wide variety of pathogens, increased significantly. Bacillus administration resulted in normal levels of abundance of Firmicutes and Proteobacteria. Analysis of bacterial genera showed that Salmonella challenge decreased the population of Lactobacillus, the most abundant genus, and increased populations of Pseudomonas and Flavobacterium genera by a factor of 3 to 5. On the other hand, Bacillus administration caused the abundance of the Lactobacillus genus to recover to control levels and decreased the population of Pseudomonas significantly. Further analysis of operational taxonomic units revealed a high abundance of genes associated with two-component systems and secretion systems in the SAL group, whereas the PRO group had more genes associated with ribosomes. Conclusion: The results of this study indicate that B. subtilis CSL2 administration can modulate the microbiota in HLB laying hens, potentially acting as a probiotic to protect against Salmonella Gallinarum infection.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.1
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• pp.37-44
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• 2016

Optical fiber temperature sensing systems have incomparable advantages over traditional electrical-cable-based monitoring systems. However, the fiber optic interrogators and sensors have often been rejected as a temperature monitoring technology in real-world industrial applications because of high cost and over-specification. This study proposes a multiplexed fiber optic temperature monitoring sensor system using an economical Optical Time-Domain Reflectometer (OTDR) and Hard-Polymer-Clad Fiber (HPCF). HPCF is a special optical fiber in which a hard polymer cladding made of fluoroacrylate acts as a protective coating for an inner silica core. An OTDR is an optical loss measurement system that provides optical loss and event distance measurement in real time. A temperature sensor array with the five sensor nodes at 10-m interval was economically and quickly made by locally stripping HPCF clad through photo-thermal and photo-chemical processes using a continuous/pulse hybrid-mode laser. The exposed cores created backscattering signals in the OTDR attenuation trace. It was demonstrated that the backscattering peaks were independently sensitive to temperature variation. Since the 1.5-mm-long exposed core showed a 5-m-wide backscattering peak, the OTDR with a spatial resolution of 40 mm allows for making a sensor node at every 5 m for independent multiplexing. The performance of the sensor node included an operating range of up to $120^{\circ}C$, a resolution of $0.59^{\circ}C$, and a temperature sensitivity of $-0.00967dB/^{\circ}C$. Temperature monitoring errors in the environment tests stood at $0.76^{\circ}C$ and $0.36^{\circ}C$ under the temperature variation of the unstrapped fiber region and the vibration of the sensor node. The small sensitivities to the environment and the economic feasibility of the highly multiplexed HPCF temperature monitoring sensor system will be important advantages for use as system-integrated temperature sensors.