• Title/Summary/Keyword: Convertible

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Application of Biocathodes in Microbial Fuel Cells: Opportunities and Challenges

  • Gurung, Anup;Oh, Sang-Eun
    • Korean Journal of Soil Science and Fertilizer
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    • v.45 no.3
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    • pp.410-420
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    • 2012
  • The heavy reliance on fossil fuels, especially oil and gas has triggered the global energy crisis. Continued use of petroleum fuels is now widely recognized as unsustainable because of their depleting supplies and degradation to the environment. To become less dependent on fossil fuels, current world is shifting paradigm in energy by developing alternative energy sources mainly through the utilization of renewable energy sources. In particular, bioenergy recovery from wastes with the help of microorganism is viewed as one of the promising ways to mitigate the current global warming crisis as well as to supply global energy. It has been proved that microorganism can generate power by converting organic matter into electricity using microbial fuel cells (MFCs). MFC is a bioelectrochemical device that employs microbes to generate electricity from bio-convertible substrate such as wastewaters including municipal solid waste, industrial, agriculture wastes, and sewage. Sustainability, carbon neutral and generation of renewable energy are some of the major features of MFCs. However, the MFC technology is confronted with a number of issues and challenges such as low power production, high electrode material cost and so on. This paper reviews the recent developments in MFC technology with due consideration of electrode materials used in MFCs. In addition, application of biocathodes in MFCs has been discussed.

A Study on the Satisfaction in Relation to Size Fit and Clothing Design of Nurse Uniform (간호사복의 치수적합성과 디자인 만족도에 관한 연구)

  • 김선희;류은정
    • Journal of the Korean Home Economics Association
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    • v.40 no.8
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    • pp.183-190
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    • 2002
  • This study was aimed at investigating the satisfaction in relation to clothing design and size-fit for nurse uniform in Korea. The subjects were 986 female nurses working in 12 hospitals selected by convenience sampling. The data were collected by questionnaires. Using SPSS package, frequency, percentage, t-test, ANOVA and SNK test were conducted. The results were divided into 2 categories as fellows; 1) Results of the satisfaction with the size-fit and size system of the nurse uniforms : Nurses satisfied at the individual size-fit system than ready-made size system. There was a considerable difference of the satisfaction with the size-fit depending on age and clinical career. And more than half of nurses were needed the concrete and precise size system. 2) Results of the actual design condition and clothing satisfaction : Nurses wore two-piece pants suits more than classical designed one-piece style. The princess-line, convertible collar and yoke design were preferred for nurse uniform with the high satisfaction. 41.6 percent of respondents used the cap obligatory and the white color and a patterned textile were generally used. The used fabrics were only polyester and cotton/polyester mixed spinning.

Inter-Domain Signal Transmission within the Phytochromes

  • Song, Pill-Soon
    • BMB Reports
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    • v.32 no.3
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    • pp.215-225
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    • 1999
  • Phytochromes (with gene family members phyA, B, C, D, and E) are a wavelength-dependent light sensor or switch for gene regulation that underscore a number of photo responsive developmental and morphogenic processes in plants. Recently, phytochrome-like pigment proteins have also been discovered in prokaryotes, possibly functioning as an auto-phosphorylating/phosphate-relaying two-component signaling system (Yeh et al., 1997). Phytochromes are photochromically convertible between the light sensing Pr and regulatory active Pfr forms. Red light converts Pr to Pfr, the latter having a "switch-on" conformation. The Pfr form triggers signal transduction pathways to the downstream responses including the expression of photosynthetic and other growth-regulating genes. The components involved in and the molecular mechanisms of the light signal transduction pathways are largely unknown, although G-proteins, protein kinases, and secondary messengers such as $Ca^{2+}$ ions and cGMP are implicated. The 124-127 kDa phytochromes form homodimeric structures. The N-terminal half contains the tetrapyrrolic phytochromobilin for red/far-red light absorption. The C-terminal half includes both a dimerization motif and regulatory box where the red light signal perceived by the chromophore-domain is recognized and transduced to initiate the signal transduction cascade. A working model for the inter-domain signal communication within the phytochrome molecule is proposed in this Review.

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Development of Driving System for Power Add-on Drive Wheelchair (수전동 휠체어용 구동장치 개발)

  • Hong, Eung-Pyo;Kim, Yong-Cheol;Kim, Gyoo-Suk;Ryu, Jae-Cheong;Mun, Mu-Seong
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.9
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    • pp.1110-1118
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    • 2011
  • The recent power add-on drive wheelchairs (PADWs) provide greater physical activity and easier transportability and may be an excellent alternative for the typical manual and powered wheelchairs. The driving system consists of a motor and a motor driver is the most important component of the PADW In this paper, design, implementation, and testing of a driving system for a PADW are presented. To design the output power and torque for the driving system, the equation of motion has been investigated. The motor and driver were fabricated with precise machining and assembled to implement our prototype driving system. The dynamometer test has been carried out using the prototype in order to examine the torque of the system. The experimental results demonstrates that the designed driving system can provide enough output power and efficiency for utilization in a PADW.

A Study on the Change in Chinese Women's Clothing during the First Half of the 20th Century (20세기 전반기 중국 여성복의 변천에 관한 연구)

  • Cho, Yong-Ran;Lee, Keum-Hee
    • The Research Journal of the Costume Culture
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    • v.16 no.4
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    • pp.661-680
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    • 2008
  • The purpose of this study is to examine to change in the Chinese women's clothing according to the inflow of Western culture in the first half of the both century As for the research method, both literature and visual data are reviewed. Research results are as follows: The Step of transition in clothing by period followed beginning stage, adopted stage, early developed stage, fully developed stage, and static stage. fully developed stage showed a perfect compromise while being applied to Chinese costume with being introduced a three-dimensional cutting method of western clothing even to the constitution as well as to the appearance. Design elements from western clothing are as follows. The transition of silhouette is box silhouette, trapeze silhouette, shift silhouette, and fitted silhouette. In detail and trimming, tailored, band, convertible, shirts collar and zigzag, scallop, camisole neckline and puff, cap sleeve and flounced, bell shaped cuffs and western button, zipper, etc. are adopted. Finally, the Chinese modern style are formed by accepting and transforming the western clothing based on the traditional Chinese clothing.

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Design and Control of 6 D.O.F(Degrees of Freedom) Hovering AUV (6자유도 호버링 AUV의 설계 및 제어)

  • Jeong, Sang-Ki;Choi, Hyeung-Sik;Seo, Jung-Min;Tran, Ngoc Huy;Kim, Joon-Young
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.9
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    • pp.797-804
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    • 2013
  • In this paper, a study of a new hovering six dof underwater robot with redundant horizontal thrusters, titled HAUV (hovering AUV), is presented. The results of study on the structure design, deployment of thrusters, and development of the developed control system of the AUV was presented. For the HAUV structure, a structure design and an analysis of the thrusting system was performed. For navigation, a sensor fusion board which can proceed various sensor signals to identify correct positions and speeds was developed and a total control system including EKF (Extended Kalman Filter) was designed. Rolling, pitching and depth control tests of the HAUV have been performed, and relatively small angle error and depth tracking error results were shown.

A Fundamental Study on the Development of a Variable Preload Device Using Toggle Joint Mechanism (토글 조인트장치를 이용한 가변예압장치 개발을 위한 기초 연구)

  • Choi, Chi Hyuk;Cha, Na Hyeon;Lee, Choon Man
    • Journal of the Korean Society for Precision Engineering
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    • v.30 no.3
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    • pp.260-265
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    • 2013
  • To increase the machine accuracy by improving the stiffness of spindle bearings, preload was applied to the spindle bearings. The methods of fixed position preload, convertible preload, constant pressure preload, and variable preload are used to apply the preload to the spindle bearing. The previous studies performed by the author of this study were variable preload methods using rubber pressure and centrifugal force based on mechanical systems. This study proposed a toggle joint mechanism that could be applied to variable preload method using centrifugal force and rubber pressure to increase the preload. Also, a finite element analysis was conducted to predict the deformation of the rubber and change of the preload. And the analysis results showed that the preload by the device using rubber pressure only was increased by the toggle joint mechanism using rubber pressure.

Development of In-wheel Motor for Power Add-on Drive Wheelchair (수전동 휠체어용 모터 개발)

  • Hong, Eung-Pyo;Park, Sei-Hoon;Oh, Hong-Seok;Ryu, Jae-Cheong;Mun, Mu-Seong
    • Journal of the Korean Society for Precision Engineering
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    • v.28 no.8
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    • pp.992-999
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    • 2011
  • The recent power add-on drive wheelchairs (PADWs) provide greater physical activity, are easier to transport, and may be an excellent alternative for the typical manual or electric wheelchairs. The development of in-wheel motor for a PADW is the principal issues. In this paper, design, implementation, and testing of the permanent magnet synchronous motor (PMSM) for a PADW are presented. To design output power and torque of the motor, the equation of motion has been investigated. The design parameters were calculated and the dimension and shape of the motor which was limited by the In-wheel mechanism of the PADW were done by applying FEM and optimal design technique. The prototype of the motor mentioned above was fabricated with precise machining and assembling. Then the motor tested on dynamometer and the measured results of the motor were verified by comparing the design results. The fabricated motor was 80 mm in length with a diameter of 110 mm and small enough to be attached the driving unit of the PADW.

A Study on Design of High Power Permanent Magnet Propulsion Motor with Convertible Phase Winding in Ship (상 변환이 가능한 대용량 영구자석형 선박 추진전동기 설계에 관한 연구)

  • Kim, Dong-Sok;Park, Gwan-Soo;Kim, Han-Deul;Shin, Pan-Seok
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.835-836
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    • 2006
  • 최근의 선박 추진시스템은 기존의 엔진, 터빈 등의 구동 원에서 선박의 발전기로부터 선체 외부의 프로펠러와 일체형으로 구성된 모터를 구동하여 추진하는 전기추진식으로 변화되고 있다. 특히, 히토류계 영구자석재질의 발달로 인하여 대형 선박의 추진을 위한 대용량 자석계자형 BLDC와 영구자석형 동기전동기의 설계가 가능해 졌으며, 이에 대한 연구구도 활발히 이루어지고 있다. 그러나 이도 중 소형 선박기기에 한정되어 있으며, MW급 이상의 대형기기의 설계 연구도 일부 선진국에서만 진행 되고 있는 실정이다. 이에 본 연구에서는 5MW, 150rpm급 대용량 추진전동기 설계에 관한 연구를 하였다. 본 설계 모델은 오랜 기간 해양 운행을 해야 하는 선박특성 상 중요한 부분인 에너지 효율을 높이기 위하여 인버터를 전동기 내부에 배치한 구조로 부피와 중량을 줄이고, 더불어 속도에 따라 인버터를 커플링하여 상변환이 가능한 전동기를 설계하였다.

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A Study on the Improvement of Clearance Procedure for Electronic Trade (전자무역을 위한 통관업무의 개선에 관한 연구)

  • Lee, Bong-Soo
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.37
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    • pp.253-273
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    • 2008
  • The thesis examines the problems for improvement of clearance procedure and shows the various ways of overcoming them. Practical implications regarding the innovation of clearance procedure are as follows. First, the basis of information for customs clearance service should be built for unifying customs clearance information and imports and exports goods. Second, Customs Service need to keep on trying continuously that customs clearance system should be inter-convertible in the inside and outside of the country. Third, reliable law and execution system should be needed to revitalize customs clearance business and the government need to take measures for new system which is suitable for our own country. Finally, mutual cooperation administration system for customer in domestic and foreign country should be made for supplying high quality clearance service. As we have reviewed above contents, the customs clearance business meet the needs of innovation with new information technique to overcome lots of problems which come by when we execute simplification of customs clearance procedure and customs inspection administration fairly. As well as, when we review a few methods in the line of our customs system, we need strongly completion of related system and arrangements in trade business and similar fields. Hereafter we hope the limitation of this study should be overcome by the process of proper inspections through subsequent studies.

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