• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2004년도 SMICS 2004 International Symposium on Maritime and Communication Sciences
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• pp.9-15
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• 2004

The copolymerization of HEMA with different hydrophilic and hydrophobic co-monomers allows for the manipulation of their intrinsic properties. 2-Hydroxyethylmethacrylate (HEMA)-based hydrogels thus are of great interest due to their outstanding physico-mechanical properties and chemical stability. The idea to use HEMA in order to create thermo-sensitive polymers was based on our assumption that thermal-sensitivity comes from a suitable hydrophilic-hydrophobic balance of macromolecules. In this work we have chosen N-vinyl pyrrolidone as a hydrophilic co-monomer with the relatively hydrophobic HEMA due to its good polymerizing properties as well as its non-toxicity in a polymer state and deserved recognition as a biocompatible material. As a result, copolymerization of NVP and HEMA was successful in obtaining new types of thermo-sensitive polymers composed of hydrophilic and hydrophobic monomers.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 추계학술대회
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• pp.714-715
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• 2017

일본 후쿠시마 원전 사고로 해양에 많은 방사능이 누출되면서 해양 방사선 탐지에 대한 많은 관심이 고조되었다. 본 논문에서는 해양에서 방사선 탐지를 위한 MCNP 시뮬레이션을 하였다. 공기중과 달리 해양환경은 수심, 온도, 압력, 염분 등으로부터 센서의 안정성을 확보해야한다. 또한, 해양환경에서는 방사선이 많이 차폐된다. 따라서 방사선 차폐율이 낮은 하우징을 선택하는 것이 목적이다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1363-1364
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• 2007

The composites such as Sn-CNTs, $SnSb_{0.5}$-CNTs and $CoSb_3$-CNTs have attracted much attention in the past years owing to their good overall properties. In these samples, intermetallic compounds show high specific capacities. Recently, interest in metal oxides such as $Al_{2}O_{3}$, MgO and $TiO_2$ has been largely stimulated by the realization that they can improve the cycling stability of the Li-ion battery electrodes. The reversible capacity of the $TiO_2$/CNTs composite reaches 168 mAh $g^{-1}$ at the first cycle and remains almost constant during long-term cycling. In this study, a nanocomposite of $TiO_2$/CNTs was prepared by sol-gel method and its electrochemical properties as anode materials for Li-ion batteries were studied by galvanostatic cycling, cyclic voltammograms (CV) and electrochemical impedance spectroscopy (EIS).

• 세라미스트
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• 제21권4호
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• pp.349-365
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• 2018

Since the electrification of vehicles has been extended, solid-state batteries have been attracting a lot of interest because of their superior safety. Especially, polymer, sulfide, and oxide based materials are being studied as solid electrolytes, and each type of materials has advantaged and disadvantages over others. Oxide electrolytes has higher chemical and electrochemical stability compared to the other types of electrolytes. However, ionic conductivity isn't high enough as much as that of organic liquid electrolytes. Also, there are many difficulties of fabricating solid-state batteries with oxide based electrolytes because they require a sintering process at very high temperature (above ${\sim}800^{\circ}C$). Herein, we review recent studies of solid-state batteries with oxide based electrolytes about the ionic conductivity, interfacial reactions with Li metal, and preparation of solid-state cell.

• Wind and Structures
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• 제19권4호
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• pp.353-370
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• 2014

A new method is proposed in this study for estimating the damping ratio of a super tall building under strong wind loads with short-time measured acceleration signals. This method incorporates two main steps. Firstly, the power spectral density of wind-induced acceleration response is obtained by the wavelet transform, then the dynamic characteristics including the natural frequency and damping ratio for the first vibration mode are estimated by a nonlinear regression analysis on the power spectral density. A numerical simulation illustrated that the damping ratios identified by the wavelet spectrum are superior in precision and stability to those values obtained from Welch's periodogram spectrum. To verify the efficiency of the proposed method, wind-induced acceleration responses of the Guangzhou West Tower (GZWT) measured in the field during Typhoon Usagi, which affected this building on September 22, 2013, were used. The damping ratios identified varied from 0.38% to 0.61% in direction 1 and from 0.22% to 0.59% in direction 2. This information is expected to be of considerable interest and practical use for engineers and researchers involved in the wind-resistant design of super-tall buildings.

• Journal of Microbiology and Biotechnology
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• 제29권7호
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• pp.1009-1013
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• 2019

Polymeric nanoparticles are widely used for drug delivery due to their biodegradability property. Among the wide array of polymers, chitosan has received growing interest among researchers. It was widely used as a vehicle in polymeric nanoparticles for drug targeting. This review explored the current research on the antimicrobial activity of chitosan nanoparticles (ChNP) and the impact on the clinical applications. The antimicrobial activities of ChNP were widely reported against bacteria, fungi, yeasts and algae, in both in vivo and in vitro studies. For pharmaceutical applications, ChNP were used as antimicrobial coating for promoting wound healing, preventing infections and combating the rise of infectious disease. Besides, ChNP also exhibited significant inhibitory activities on foodborne microorganisms, particularly on fruits and vegetables. It is noteworthy that ChNP can be also applied to deliver antimicrobial drugs, which further enhance the efficiency and stability of the antimicrobial agent. The present review addresses the potential antimicrobial applications of ChNP from these few aspects.

• 한국포장학회지
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• 제24권3호
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• pp.167-180
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• 2018

Interest in the use of smart packaging systems for food products has increased in recent years. Therefore, food researchers are focusing on the development of new indicator based smart packaging technologies by using anthocyanin-based natural dye. Anthocyanins are one of the plant constituents known as flavonoids and responsible for the bright and attractive orange, red, purple, and blue colors of most fruits, vegetables, flowers, and some cereal grains. Indicators of natural dyes such as anthocyanins could express the quality and shelf life of perishable food products. However, the sensitivity and stability for their use in smart food packaging should be established to reach the market proposals. This review article focuses on recent studies related to use of natural dyes based on anthocyanin for smart food packaging applications. This study offers valuable insight that may be useful for identifying trends in the commercialization of natural dyes or for identifying new research areas. This review also provides food and packaging scientists with a thorough understanding of the benefits of anthocyanin-based natural dyes for shelf life indicator when applied to package material specific foods and hence can assist in accelerating commercial adoption.

• 드라이브 ㆍ 컨트롤
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• 제15권4호
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• pp.74-80
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• 2018

A damper is a hydraulic device designed to absorb or eliminate shock impulses which is acting on the sprung mass of vehicle. It converting the kinetic energy of the shock into another form of energy, typically heat. In a vehicle, a damper reduce vibration of car, leading to improved ride comfort and running stability. Therefore, a damper is one of the most important components in a vehicle suspension system. Conventionally, the design process of vehicle suspensions has been based on trial and error approaches, where designers iteratively change the values of the design variables and reanalyze the system until acceptable design criteria are achieved. Therefore, the ability to tune a damper properly without trial and error is of great interest in suspension system design to reduce time and effort. For this reason, a many previous researches have been done on modeling and simulation of the damper. In this paper, we have conducted optimal design process to find optimal design parameters of damping force which minimize a acceleration of sprung mass for a given suspension system using genetic algorithm.

• The Journal of Asian Finance, Economics and Business
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• 제8권4호
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• pp.797-808
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• 2021

This study examines the interaction between internal auditors' personality traits and the internal audit function effectiveness. It also investigates the effect of such interacted variables on financial reporting quality. This study employed a questionnaire survey to collect data from 193 internal auditors of Jordanian companies listed on the Amman Stock Exchange. The study model is validated and tested using the partial least squares structural equation modelling. The results reveal that all the examined personality traits of internal auditors significantly impact internal audit function effectiveness except for the extraversion trait. The results also show that personality traits have indirect effects on financial reporting quality via internal audit function effectiveness. These results suggest that internal auditors with high scores on openness to experience, emotional stability, and conscientiousness traits can be among the most significant contributors to the internal audit function effectiveness. The results also suggest that internal auditors' personality traits can be regarded as an internal audit function intangible resource that enhances effectiveness. The study's findings might be of interest to many different parties interested in enhancing internal audit function effectiveness and boosting the financial reporting quality, such as external and internal auditors, auditees, human resource departments, and Chief Internal Audit Executives.

• The Journal of Asian Finance, Economics and Business
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• 제8권3호
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• pp.1113-1119
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• 2021

This study aims to determine the impact of the news coverage of the COVID-19 pandemic on the composite stocks' movement (IHSG) in Indonesia. This study used secondary data of daily time series with an observation range of March 2020-June 2020. This study used three main variables, namely, COVID-19 news, the daily price of a composite stock market index (IHSG), and interest rate. This study clarifies pandemic news into two forms to facilitate quantitative analysis, namely, good news and bad news. Both pandemic news conditions, which have been clarified, are then processed into the index and reprocessed along with two other variables using vector autoregressive (VAR). The results showed that the good news have a dominant effect on developing the composite stock price index (IHSG) in Indonesia during the COVID-19 pandemic. Although the good news dominates the composite stock price index (IHSG) movement in Indonesia, the bad news must also be anticipated. By implementing a series of macroeconomic policies that follow the conditions of the composite stock price index (IHSG) movements on the stock exchange floor, the bad news response can decrease the potential for a decline in investor confidence, so that the financial system's macroeconomic stability is maintained.