• Title/Summary/Keyword: self -assembly

Search Result 690, Processing Time 0.026 seconds

The Effect of Industrial Health Education on Workers' Health Status : focusing on Small and Medium Industries (산업장 보건교육과 근로자 건강상태에 관한 연구 -일부 중소규모 산업장을 중심으로-)

  • 송현종;이명선
    • Korean Journal of Health Education and Promotion
    • /
    • v.15 no.2
    • /
    • pp.1-21
    • /
    • 1998
  • The industrial health education is the most fundamental and active area in the industrial health. It has become increasingly recognized as an important component of preventive occupational health programs and is an essential service for improvement of productivity and employee's health. Evaluating the worker's health status is a part of the occupational health promotion policy and is very important to know the efficiency of the occupational health service. In this point, the purpose of this study was to clarify the effect of the industrial health education on worker's health status. This study included a survey of 625 workers at 28 factories in Puchon area form August Z7 to September 30, 1996. The research was carried out through the analysis of the self-administered questionnaires and health examination records. The results were as follows: 1. For demographic characteristics, 66.5% of the respondents were male. The most prevalent age group was 30 - 39years group(30.4%). Those who graduated from high school were 43.5%. The workers whose monthly income ranged from 600,000 to 100,000 won were 40.3%. As for the marital status, 69.4% of the respondents were married. 2. For occupational characteristics, 37.9% of the workers had worked 2 to 5 years in the factories, 69.4% of the respondents worked at the assembly line and the staffs were 27.0%. T26.4% of the respondents worked at hazardous workplace and 71.8% of the workers worked 9 to 10 hours a day. Those who worked during the night were 56.0%. Those who felt much for them workload were 29.9% and were dissatisfied with their working environment and job were 33.6%, 19.1%. 3. The 39.4% of the respondents received the industrial health education and most of them received on the safety and only few on family health. 70.7% out of those who had industrial health education reported it helped their health management.

  • PDF

Direct Simulation of the Magnetic Interaction of Elliptic Janus Particles Suspended in a Viscous Fluid (점성유체에 분산된 타원형 야누스 입자의 자성 상호작용에 관한 직접수치해석)

  • Kim, Hei Eun;Kang, Tae Gon
    • Transactions of the Korean Society of Mechanical Engineers B
    • /
    • v.41 no.7
    • /
    • pp.455-462
    • /
    • 2017
  • The magnetic interaction between elliptic Janus magnetic particles are investigated using a direct simulation method. Each particle is a one-to-one mixture of paramagnetic and nonmagnetic materials. The fluid is assumed to be incompressible Newtonian and nonmagnetic. A uniform magnetic field is applied externally in a horizontal direction. A finite-element-based fictitious domain method is employed to solve the magnetic particulate flow in the creeping flow regime. In the magnetic problem, the magnetic field in the entire domain, including the particles and the fluid, is obtained by solving the governing equation for the magnetic potential. Then, the magnetic forces acting on the particles are calculated via a Maxwell stress tensor formulation. In a single particle problem, it is found that the orientation angle at equilibrium is affected by the aspect ratio of the particle. As for the two-particle interaction, the dynamics and the final conformation of the particles are significantly influenced by the aspect ratio, the orientation, and the spatial positions of the particles. For the given positions of the particles, the fluid flow is also influenced by the orientation of each particle. The self-assembly structure of the particles is not a fixed one, but it varies with the above-mentioned factors.

Design of Radio Frequency Test Set for TC&R RF Subsystem Verification of LEO and GEO Satellites (저궤도 및 정지궤도위성의 TC&R RF 서브시스템 검증을 위한 RF 시험 장비 설계)

  • Cho, Seung-Won;Lee, Sang-Jeong
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.42 no.8
    • /
    • pp.674-682
    • /
    • 2014
  • Radio Frequency Test Set (RFTS) is essential to verify Telemetry, Command & Ranging (TC&R) RF subsystem of both Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO) satellite during Assembly Integration & Test (AI&T). The existing RFTS was specialized for each project and needed to be modified for each new satellite. The new design enables RFTS to be used in various projects. The hardware and software was designed considering this and therefore it could be directly used in other projects within a similar test period without modification or inconvenience. It will be also easily controlled, modified, and managed through the extension in modularization according to each function and the use of COTS (commercial on-the-self) and this will improve system reliability. A more reliable RF test measurement is also provided in this new RFTS by using an accurate reference clock signal.

Expression and Purification of Soybean Protein from Escherichia coli (콩 단백질의 대장균 발현과 정제)

  • 오문헌;정재홍;노영희;이희봉
    • The Korean Journal of Food And Nutrition
    • /
    • v.9 no.4
    • /
    • pp.404-408
    • /
    • 1996
  • One of the major objectives of the food industry is the enrichment of the functional properties and nutritional value of soybean protein. To attain this goal, an expression system of cDNA encoding native and protein-engineered soybean proteins in a microorganism must be developed and the function then ability of self-assembly and the functionalities of the expressed proteins should be evaluated before the modified genes are transfered to soybean plants. The pro-$\beta$-conglycinin synthesized in E. coli BL21(DE3) comprised approximately 20% of the total bacterial proteins and the expressed protein are formed soluble and trimer such as native protein in E. coli cells. The highly expressed protein was purified to homogeneity by salt precipitation with 20~40$ Ammonium sulfate ion-exchange chromatography with Q-Sepharose and hydrophobic column chromatography with Butyltoyopearl. Therefore, we concluded that the high-level expression system of $\beta$-conglycinin cDNA was established and a relatively simple and rapid method for purifying pro-$\beta$-conglicinin was also developed.

  • PDF

A wireless impedance analyzer for automated tomographic mapping of a nanoengineered sensing skin

  • Pyo, Sukhoon;Loh, Kenneth J.;Hou, Tsung-Chin;Jarva, Erik;Lynch, Jerome P.
    • Smart Structures and Systems
    • /
    • v.8 no.1
    • /
    • pp.139-155
    • /
    • 2011
  • Polymeric thin-film assemblies whose bulk electrical conductivity and mechanical performance have been enhanced by single-walled carbon nanotubes are proposed for measuring strain and corrosion activity in metallic structural systems. Similar to the dermatological system found in animals, the proposed self-sensing thin-film assembly supports spatial strain and pH sensing via localized changes in electrical conductivity. Specifically, electrical impedance tomography (EIT) is used to create detailed mappings of film conductivity over its complete surface area using electrical measurements taken at the film boundary. While EIT is a powerful means of mapping the sensing skin's spatial response, it requires a data acquisition system capable of taking electrical impedance measurements on a large number of electrodes. A low-cost wireless impedance analyzer is proposed to fully automate EIT data acquisition. The key attribute of the device is a flexible sinusoidal waveform generator capable of generating regulated current signals with frequencies from near-DC to 20 MHz. Furthermore, a multiplexed sensing interface offers 32 addressable channels from which voltage measurements can be made. A wireless interface is included to eliminate the cumbersome wiring often required for data acquisition in a structure. The functionality of the wireless impedance analyzer is illustrated on an experimental setup with the system used for automated acquisition of electrical impedance measurements taken on the boundary of a bio-inspired sensing skin recently proposed for structural health monitoring.

School Based Intervention with Mental Health Problem in the Elementary School : Systematic Review (정신건강 어려움이 있는 국내 초등학생의 학교-기반 중재 : 체계적 고찰)

  • Kim, Ki-Woong;Cho, Sun-Young
    • The Journal of the Korea Contents Association
    • /
    • v.18 no.10
    • /
    • pp.335-347
    • /
    • 2018
  • The purpose of this study was to find more effective mental health intervention for school based intervention with mental health problem in an elementary school. A systematic review was conducted according to the PRISMA checklist. We accessed databases including RISS, KISS, and the National Assembly Library of Korea. Subject studies were classified according to type of intervention, subject characteristic, and evaluation. Finally, twenty-five studies matched the inclusion criteria. According to types of intervention, it was classified into four types which are psychoeducation(self-management skills, social skills, social emotional learn ing), behavior intervention(positive behavior support, modeling), psychotherapy(art therapy, counseling and parent coaching), and recreation intervention(robot intervention, horticultural therapy). The most of subjects were intellectual disability, the following subjects were ADHD. The most areas of evaluation were emotional change and attention. The findings of this review support school based intervention and provide evidence. And it can be used as an important basic data for preparing more effective mental health-related school-based interventions.

Shape control of ZnO thin films and nanorods grown by metalorganic chemical vapor deposition (MOCVD 법으로 저온에서 성장한 ZnO 박막과 나노구조의 모양변화)

  • Kim, Dong-Chan;Kong, Bo-Hyun;Kim, Young-Yi;Jun, Sang-Ouk;An, Cheal-Hyoun;Cho, Hyung-Koun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2006.11a
    • /
    • pp.21-21
    • /
    • 2006
  • 21세기 정보통신 및 관련 소재의 연구방향은 새로운 기능성 확보, 극한적 제어성, 복합 및 융합이라는 경향으로 발전해 가고 있다. 반도체 기술 분야에서 현재의 공정적 한계를 극복하고 새로운 기능성을 부여하기 위해 나노 합성과 배열을 기본으로 하여 bottom-up 방식의 나노소자 구현이 큰 주목을 받고 있다. 나노선의 경우 나노 스케일의 dimension, 양자 제한 효과, 우수한 결정성, self-assembly, internal stress 등 기존 벌크형 소재에서 발견할 수 없는 새로운 기능성이 나타나고 있어 바이오, 에너지, 구조, 전자, 센서 등의 분야에서의 활용이 가능하다. 현재 국내외적으로 반도체 나노선으로 널리 연구되고 있는 재료는 ZnO, $SnO_2$, SiC 등이 중심이 되고 있다. 이중 ZnO 나 노선의 합성을 위해서는 thermal CVD, MOCVD, PLD, wet-chemical 등 다양한 방법이 사용되고 있다. 특히 MOCVD 방법에 의해 수직 정렬된 ZnO 나노막대를 성장할 수 있다. 이러한 나노막대는 MO 원료 및 산소 공급량을 적절히 제어함으로서 수직 배향 및 나노선의 구경 제어가 가능하며, 나노 막대의 크기 제어와 관련해서는 반응 관내의 DEZn 와 $O_2$의 양을 변화시켜 구조체의 크기를 수 십 ~ 수 백 나노미터의 크기로 제어할 수 있다. 본 연구는 이러한 ZnO 나노선의 성장과정에서 $210^{\circ}C$ 이하의 저온에서 성장한 ZnO 버퍼층을 이용해 나노구조의 형상을 제어하고자 하였다. 특히 ZnO 저온 버퍼층의 두께에 따라 나노막대의 직경변화, 수직배향성, 형상변화의 제어가 가능하였다. 나노막대의 특성 평가는 TEM, SEM, PL, XRD 등을 이용하여 구조적, 결정학적, 광학적 특성을 분석하였다.

  • PDF

UV를 이용한 IGZO 표면 상태 변화 및 전기적 특성 변화

  • Jo, Yeong-Je;Choe, Deok-Gyun;Mun, Yeong-Ung
    • Proceedings of the Materials Research Society of Korea Conference
    • /
    • 2011.05a
    • /
    • pp.242.1-242.1
    • /
    • 2011
  • 산화물 반도체는 높은 이동도와 낮은 공정 온도, 넓은 밴드갭으로 인한 투명성등 많은 장정을 가지고 있어 최근 많이 연구되고 있다. 그 중에서도 InGaZnO (IGZO)는 In, Ga 함유량으로 박막의 전기적 특성을 쉽게 조절할 수 있고 상온에서 비정질 상태로 증착되어 균일성에 장점이 있다. IGZO 박막을 TFT에 적용 시 MOSFET과는 다르게 축적 상태에서 채널이 형성되기 때문에 산화물 반도체 내에 캐리어 농도는 TFT 특성에 많은 영향을 미친다. 또한, 실리콘 기반의 트랜지스터는 이온 주입 및 확산 공정을 통해서 선택적으로 $10^{20}/cm^3$ 이상의 고농도 도핑을 실시하여 좋은 트랜지스터 특성을 확보할 수 있으나 IGZO 박막에는 이러한 접근이 불가능하다. 따라서 IGZO 박막의 캐리어 농도를 조절할 수 있으면 소스/드레인과 반도체의 접촉 저항 감소 및 전계 효과 이동도등 많은 특성을 개선할 수 있다. 본 연구에서는 UV light를 이용하여 IGZO 박막의 캐리어 농도를 조절하였다. IGZO 박막은 UV light 조사로 인해 Mo와 IGZO박막의 접촉저항이 $3{\times}10^3\;{\Omega}^*cm$에서 $1{\times}10^2\;{\Omega}^*cm$로 감소하였다. 이는 UV 조사로 표면에 금속-OH 결합이 생성되어 IGZO 박막의 캐리어 농도가 ${\sim}5{\times}10^{15}/cm^3$에서 ${\sim}3{\times}10^{17}/cm^3$까지 증가하기 때문이다. 또한 표면에 생성된 OH기는 강한 친수성 성질을 보여주고 표면의 높은 에너지 상태는 Self-Assembly Monolayer (SAM) 공정 적용이 가능 하다. 본 실험에서는 SAM 공정을 적용하여 IGZO-based TFT 제작에 성공하였고, 이 TFT는 UV 조사 시간에 따라 전계 효과 이동도가 0.03 $cm^2/Vs$에서 2.1 $cm^2/Vs$으로 100배 정도 증가하였다.

  • PDF

Meanings and Tasks of the Three Revised Bills which Ease Regulations on the Use of Personal Information (데이터 3법 개정의 의미와 추후 과제)

  • Kim, Seo-An
    • Convergence Security Journal
    • /
    • v.20 no.2
    • /
    • pp.59-68
    • /
    • 2020
  • In January 2020, the National Assembly passed the revisions of three bills which ease regulations on the use of personal information. The revised laws include the launch of an independent supervisory body, the arrangement of redundant regulations, and regulations for the development of the data economy. This paper analyzes the content and meaning of each law of the Three Revised Bills that Ease Regulations on the Use of Personal Information. And the future challenges outline three aspects: the establishment of a system to ensure the right to informational self-determination of privacy concerns, the establishment of a certification system and the presentation of reasonable guidelines, and the expectation of professional performance by the Personal Information Protection Commission.

Changes of dielectric surface state In organic TFTs on flexible substrate (유연한 기판상의 유기 트랜지스터의 절연 표면층 상태 변화에 의한 전기적 특성 향상)

  • Kim, Jong-Moo;Lee, Joo-Woo;Kim, Young-Min;Park, Jung-Soo;Kim, Jae-Gyeong;Jang, Jin;Oh, Myung-Hwan;Ju, Byeong-Kwon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2004.05a
    • /
    • pp.86-89
    • /
    • 2004
  • Organic thin film transistors (OTFTs) are fabricated on the plastic substrate through 4-level mask process without photolithographic patterning to yield the simple fabrication process. And we herewith report for the effect of dielectric surface modification on the electrical characteristics of OTFTs. The KIST-JM-1 as an organic molecule for the surface modification is deposited onto the surface of zirconium oxide $(ZrO_2)$ gate dielectric layer. In this work, we have examined the dependence of electrical performance on the interface surface state of gate dielectric/pentacene, which may be modified by chemical properties in the gate dielectric surface.

  • PDF