• 제목/요약/키워드: Electronic safety

검색결과 1,523건 처리시간 0.03초

보조접지그리드의 시설에 의한 대지표면전위경도의 저감 (Reduction of the the Ground Surface Potential Gradients by Installing Auxiliary Grounding Grids)

  • 이승칠;엄주홍;이복희;김효진
    • 조명전기설비학회논문지
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    • 제16권2호
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    • pp.121-129
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    • 2002
  • 본 논문에서는 효과적인 접지그리드 설치기법에 대하여 기술하였으며, 낙뢰나 지락고장서지, 개폐서지 등으로 부터 인체의 감전보호나 컴퓨터를 비롯한 전기·전자기기의 보호를 위한 접지그리드의 시설 및 배치방법에 따른 실험적인 평가를 수행하였다. 접지그리드의 배치에 따른 대지표면전위경도의 분석과 위험전압으로 작용하는 대지 표면전위상승의 억제에 주안점을 두고 실험용 모델접지전극을 시설한 후 임 펄스전류를 인가하였다. 기존의 등간격 접지그리드의 결점을 보완하기 위해 접지그리드에 경사를 가지는 보조접지그리드를 시설하였으며, 보조접지그리드를 시설한 접지시스템에서는 인체나 전기·전자기기에 위험전압으로 작용하는 대지표면전위경도를 최대 50%이상 완화시키는 효과를 얻었다.

CFC 대체세정제의 물성 비교 (Comparison of Physical Properties of CFC Alternative Cleaning Solvents)

  • 노경호;이윤용
    • 분석과학
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    • 제6권1호
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    • pp.65-75
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    • 1993
  • 오존층 파괴물질로 규명된 CDC 113의 대체 세정제를 수집하여 실험적인 방법으로 밀도, 표면장력, 굴절지수, 비점, pH, 점도, 인화점, 용해도를 측정하였다. 대체세정제는 크게 수계 세정제, 준수계 세정제, 알코올 및 케톤계 세정제, 할로겐 세정제로 나누어서 측정한 물성들을 비교하였다. 전자산업의 잔자회로기판(PCB)에 사용되는 flux의 주성분인 abietic acid와 각 세정제의 용해실험은 HPLC를 사용하여 용해도를 구하였다. 각 분류별 세정제는 장단점을 갖추고 있으며 최종 사용자는 물성에 의한 세정제의 효율성과 세정방법 뿐만 아니라 안정성, 경제성을 종합적으로 고려해야 한다. 본 연구의 목적은 시판중인 CFC 113의 대체 세정제를 수집하여 물성을 측정하고 비교함으로써 사용자가 원하는 최적의 대체 세정제를 선정하는 데 기본적인 자료를 제공하는 것이다.

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홍삼의 약리와 독성 기전에 대한 고찰 (Review of Red Ginseng in terms of Mechanisms for Pharmacodynamics and Toxicity)

  • 박영철;임정대;김종봉;이선동
    • 대한한의학회지
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    • 제33권3호
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    • pp.200-230
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    • 2012
  • Objectives: Ginseng, Panax ginseng C. A., white ginseng, has been used for thousands of years in Traditional Korean Medicine. Red ginseng can be made by a steaming process of white ginseng changing a variety of ginsenosides and ingredients such as dencichine. This article reviews red ginseng for mechanisms for pharmacodynamics and toxicity based on the content of ginseng's active ingredients, ginsenoside changed by steaming. Methods: The following electronic databases were searched: PubMed, Science Direct and Chinese Scientific Journals full text database (CQVIP), and KSI (Korean Studies Information) from their respective inceptions to June 2012. Results: Compared with unsteamed ginseng, the content of ginsenosides Rg2, Rg3, Rg5, Rh1, Rh2 and Rk1 called red ginseng-specific ginsenosides increased after the steaming process. Different ginsenosides have shown a wide variety of effects such as lowering or raising blood sugar and blood pressure or stimulating or sedating the nervous system. Especially, the levels of Rg2, Rg3, Rg5, Rh1, Rh2 and Rk1 were increased by the steaming process, showing a variety of pharmacodynamics in biological systems. Also, various processing methods such as puffing and fermentation have been developed in processing crude ginseng or red ginseng, affecting the content of ginseng's ingredients. The safety issue could be the most critical, specifically, on changed ginseng's ingredients such as dencichine. The level of dencichine was significantly reduced in red ginseng by the steaming process. In addition, the possible toxicity for red ginseng was affected by cytochrome P450, a herbal-drug interaction. Conclusions: The variety of pharmacological and toxicological properties should be changed by steaming process of Panax ginseng C. A., white ginseng. Even if it is not sure whether the steaming process of white ginseng would be better pharmacologically, it is sure that steaming reduces the level of dencichine causing a lower toxicity to the nervous system.

화이트소스를 첨가한 굴(Crassostrea gigas) 통조림의 제조 및 특성 (Preparation and Characterization of Canned Oyster Crassostrea gigas in White Sauce)

  • 차장우;이수광;박선영;강상인;강영미;김진수
    • 한국수산과학회지
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    • 제51권5호
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    • pp.491-498
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    • 2018
  • The objective of this study was to investigate the composition of canned oyster Crassotrea gigas in white sauce (CO-WS). The proximate composition of CO-WS was 74.1% water, 10.4% crude protein, 4.9% crude lipid, and 3.1% ash. The energy converted based on these percentages was 112.2 kcal/100 g, while the salinity was 1.1 g/100 g. In a taste-intensity test using an electronic tongue, the CO-WS showed higher umami taste intensity than the control (canned oyster in commercial white sauce), whereas the intensities of the other tastes (salty, sour, bitter, and sweet) were lower. Because the odor intensity was low, CO-WS was considered to have a relatively weak odor and showed no difference in hardness compared to the control. Sensory evaluation of CO-WS by a panel yielded higher scores for appearance, taste, and texture, and a lower score for flavor compared to the control. The total amino acid content of CO-WS was 8.91 g/100 g, and its major amino acids were aspartic acid, glutamic acid, and leucine. With respect to mineral content, CO-WS had higher calcium and lower zinc contents than the control. These results suggest that CO-WS has excellent nutritional value.

디지털 정보화를 통한 현장 자원 및 정보관리 기술에 관한 연구(PRIMA 시스템) (A Study on Project Resource & Information Management with Internet Application(PRIMA system))

  • 김외곤;이동렬
    • 한국건설관리학회논문집
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    • 제2권1호
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    • pp.88-97
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    • 2001
  • 새 천년의 화두로 떠오른 인터넷은 건설업의 위상을 새롭게 정립할 수 있는 도구로 활발히 연구되고 있으며 건설 CALS의 실현을 통해 건설업도 고부가가치 및 첨단산업의 대열에 동참할 수 있을 것으로 여겨진다. 이미 인터넷 입찰체계 및 건설분야 전자상거래 시스템 도입 등 다방면에 걸쳐 건설업에서도 인터넷이 점진적으로 활용되고 있지만 좀 더 다양하고 실질적인 면에서의 인터넷 활용이 요구되고 있는 실정이다. 이에 최근 건설 상황변화에 대처하기 위한 신속한 의사결정 도구 및 효율적인 관리기법의 필요성이 절실히 대두되었고 PRIMA 시스템은 공사관리를 위한 신기술로 개발되었다. 이 시스템은 인터넷을 이용한 Just In Time(JIT) 관리기법, 노무$\cdot$안전$\cdot$작업 관리의 통합 어플리케이션, 실시간 데이터에 의한 의사결정 프로세스 세가지로 구성되어 진다. PRIMA시스템은 대형공사 현장에 적용되어 이미 그 실효성을 입증 받았으며 앞으로 인터넷 환경이 좋아질수록 특정 프로젝트만의 관리 방법이 아닌 범용적 관리 기술로 자리잡게 되어 현장의 규모 및 장소에 관계없이 그 활용은 점점 확대될 것이다.

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시간-주파수 영역 반사파 계측방법을 이용한 부하 저항 측정 시스템 구현 (The Implementation of Load Resistance Measurement System using Time-Frequency Domain Reflectometry)

  • 곽기석;박태근;윤태성;박진배
    • 대한전기학회논문지:시스템및제어부문D
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    • 제55권10호
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    • pp.435-442
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    • 2006
  • One of the most important topics about the safety of electrical and electronic system is the reliability of the wiring system. The Time-Frequency Domain Reflectometry(TFDR) is a state-of-the-art system for detecting and estimating of the fault on a wiring. In this paper, We've considered the load resistance measurement on a coaxial cable using TFDR in a way of expanded application. The TFDR system was built using commercial Pci extensions for Instrumentation(PXI) and LabVIEW. The proposed real time TFDR system consisted of the reference signal design, signal generation, signal acquisition, algorithm execution and results display part. To implement real time system, all of the parts were programmed by the LabVIEW which is one of the graphical programming languages. Using the application software implemented by the LabVIEW, we were able to design a proper reference signal which is suitable for target cable and control not only the arbitrary waveform generator in the signal generation part but alto the digital storage oscilloscope in the signal acquisition part. By using the TFDR real time system with the terminal resistor on the target cable, we carried out load impedance measurement experiments. The experimental results showed that the proposed system are able not only to detect the location of impedance discontinuity on the cable but also to estimate the load resistance with high accuracy.

일개 종합병원 입원환자의 낙상관련 특성 및 낙상발생 예측요인 (Characteristics and Risk Factors for Falls in Tertiary Hospital Inpatients)

  • 최은주;이영신;양은정;김지희;김연희;박현애
    • 대한간호학회지
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    • 제47권3호
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    • pp.420-430
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    • 2017
  • Purpose: The aim of this study was to explore characteristics of and risk factors for accidental inpatient falls. Methods: Participants were classified as fallers or non-fallers based on the fall history of inpatients in a tertiary hospital in Seoul between June 2014 and May 2015. Data on falls were obtained from the fall report forms and data on risk factors were obtained from the electronic nursing records. Characteristics of fallers and non-fallers were analyzed using descriptive statistics. Risk factors for falls were identified using univariate analyses and logistic regression analysis. Results: Average length of stay prior to the fall was 21.52 days and average age of fallers was 61.37 years. Most falls occurred during the night shifts and in the bedroom and were due to sudden leg weakness during ambulation. It was found that gender, BMI, physical problems such elimination, gait, vision and hearing and medications such as sleeping pills, antiarrhythmics, vasodilators, and muscle relaxant were statistically significant factors affecting falls. Conclusion: The findings show that there are significant risk factors such as BMI and history of surgery which are not part of fall assessment tools. There are also items on fall assessment tools which are not found to be significant such as mental status, emotional unstability, dizziness, and impairment of urination. Therefore, these various risk factors should be examined in the fall risk assessments and these risk factors should be considered in the development of fall assessment tools.

탈모증의 한약제제 치료효과에 대한 체계적 문헌 고찰 (A Systematic Review of Clinical Researches of Korean Medicine for Alopecia)

  • 류덕현;노석선
    • 한방안이비인후피부과학회지
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    • 제30권2호
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    • pp.1-18
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    • 2017
  • Objectives : This review aims to evaluate a risk of bias by risk of bias tool and RoBANS(Risk of Bias Assessment tool for Non-randomized Study) tool for clinical trial papers proving treatment effect of Korean medicines to alopecia and provides the newest reason of effectiveness of herbs to alopecia. Methods : Data were collected through electronic database including NDSL, KISS, KMBASE, Koreantk, OASIS, KoreaMed, KISTI, Pubmed, Cochrane CENTRAL and CINAHL. Two experts in Oriental Medicine assessed risk of bias of randomized controlled trials by Cochrane group's Risk of Bias tool and non-randomized controlled trials by RoBANS tool after searching, reviewing and selecting papers. Results : Total number of selected trials is 20 including 4 randomized controlled trial, 13 non-randomized controlled trials and 3 case reports. This study evaluate the risk of bias of 17 papers including 4 randomized controlled trials and 13 non-randomized controlled trials except 3 case reports by risk of bias tool and RoBANS tool. All papers of randomized controlled trials are evaluated unclear for random sequence generation and allocation concealment as there are no word on them. And all papers of non-randomized controlled trials are evaluated unclear for blinding of outcome assessments and relatively low for others. Conclusions : Korean medicine intervention can be an effective for treatment in alopecia. It was evaluated by hair density, thickness and expert panel assessment of photographs and all results are statistically significant. But enhancing levels of evidence, we must try to reduce bias in researches and report a safety, protocol and IRB.

Strategic design for oxide-based anode materials and the dependence of their electrochemical properties on morphology and architecture

  • 강용묵
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2012년도 춘계학술발표대회
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    • pp.73-73
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    • 2012
  • Modern technology-driven society largely relies on hybrid electric vehicles or electric vehicles for eco-friendly transportation and the use of high technology devices. Lithium rechargeable batteries are the most promising power sources because of its high energy density but still have a challenge. Graphite is the most widely used anode material in the field of lithium rechargeable batteries due to its many advantages such as good cyclic performances, and high charge/discharge efficiency in the initial cycle. However, it has an important safety issue associated with the dendritic lithium growth on the anode surface at high charging current because the conventional graphite approaches almost 0 V vs $Li/Li^+$ at the end of lithium insertion. Therefore, a fundamental solution is to use an electrochemical redox couple with higher equilibrium potentials, which suppresses lithium metal formation on the anode surface. Among the candidates, $Li_4Ti_5O_{12}$ is a very interesting intercalation compound with safe operation, high rate capability, no volume change, and excellent cycleability. But the insulating character of $Li_4Ti_5O_{12}$ has raised concerns about its electrochemical performance. The initial insulating character associated with Ti4+ in $Li_4Ti_5O_{12}$ limits the electronic transfer between particles and to the external circuit, thereby worsening its high rate performance. In order to overcome these weak points, several alternative synthetic methods are highly required. Hence, in this presentation, novel ways using a synergetic strategy based on 1D architecture and surface coating will be introduced to enhance the kinetic property of Ti-based electrode. In addition, first-principle calculation will prove its significance to design Ti-based electrode for the most optimized electrochemical performance.

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무선통신기반 차상제어장치의 전동차 시험 분석 (Analysis of EMU Installation and Yard Test for Communication Based Train Control On-board Equipment)

  • 백종현;김용규;이창구;박재영
    • 한국산학기술학회논문지
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    • 제10권5호
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    • pp.935-941
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    • 2009
  • 본 논문에서는 철도의 운영효율을 향상시킬 수 있는 무선통신에 기반을 둔 열차제어기술에 대해 연구하였다. 현재 국내에서 사용되고 있는 신호시스템은 궤도회로 기반의 열차제어시스템으로서 열차의 이동성과 안정성을 고려하여 사용한 기술이다. 최근의 세계적 추세는 열차간격을 고밀도로 제어하기 위해 새로운 패러다임으로 떠오르고 있는 무선통신기반 열차제어시스템이다. 국내에서도 이에 대한 기술 확보가 요구되며, 이에 따른 무선통신기반 열차제어시스템의 연구개발을 추진하였다. 본 논문에서는 열차제어시스템의 구성 중 핵심적인 요소인 차상제어장치를 개발하였고, 이를 수도권 광역전철중의 하나인 분당선의 전동차에 설치하여 시험한 결과를 설명하고 있다.