• 제목/요약/키워드: Step response

검색결과 1,319건 처리시간 0.031초

유압식 어로 윈치 시뮬레이터의 동적 거동 특성 (Dynamic Characteristics of a Hydraulic Fishing Winch Simulator)

  • 이대재
    • 한국수산과학회지
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    • 제37권4호
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    • pp.330-336
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    • 2004
  • To meet the increasing demand from various fishing fields for training of fishing equipment operators, a fishing winch simulator was designed to train maritime students in the correct and safe operation of hydraulic winches under various load conditions related to fishing operations. The aim of this study is to describe the basic dynamic characteristics of the newly developed hydraulic fishing winch simulator and particularly to analyze the mechanical responses produced on the winch operation controls. The winch simulator consists of two winch units, a computer control and data acquisition system, a control consol and other associated mechanisms. When one winch is in hauling mode, the other one will always be in loading mode. The revolution speed of the hauling winch was controlled by a proportional directional control valve, and the braking torque of the loading winch was controlled by a proportional pressure control valve. The simulation experiments indicated that the dynamic characteristics of the hauling winch followed the braking response characteristics of the loading winch. The tests also showed that the warp speed and tension linearly depend on the pressure differential across the motor of the loading winch controlled by operating the proportional pressure control valve during the hauling operation. The experience gained from various training courses showed that the fishing winch simulator was very realistic and it was valuable for training novice winch operators. The results of the winch simulation exercise were recorded and used to evaluate the training on the operation and handling of the winch system. From these test results, we concluded that the tension acting on the warp during hauling operations can successfully be simulated by controlling the pressure differential across the motor with step changes of the control input signal to the proportional pressure control valve of the loading winch.

아파트 단지 인공지반의 계획적 평가에 관한 연구 (A Study on the Landscape Planning Evaluation on Apartment Artificial Ground)

  • 김유일;오정학;김인혜;윤홍범
    • 한국조경학회지
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    • 제26권3호
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    • pp.297-311
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    • 1998
  • Landscaping on artificial ground is currently served as a means to imposing a greenery benefit on high-density and high-rise apartment sites. It functions as a sub-hierarchy in apartment planning such as ornamental element from the past. Major parking space tends to be allocated on the basement area in response to the required parking regulation. Therefore, competitive relatioinship between the parking and greenery space I limited outdoor of apartments leads to the development planning strategy and technology of artificial ground. This study aims at evaluating landscape planning on artificial ground of apartment complex through several approaches such as site survey, plan drawing analysis, and interview with related field experts. 15 survey apartment sites including Bundang Model, Shindaebang-dong, Pyoungchon Hyundai Apartments have been selected for conducting the research. Main results of this study are summarized below : First, scattering allocation of artificial ground between apartment building units is a dominant plan layout type among the survey sites. Even though unifying allocation type has an advantage to maximize underground parking space, it has a difficulty in maintaining proper soil ground base for nurturing plants. Therefore, underground parking space should be planned by unifying allocation type placed separately from apartment units. This plan type can provide a balanced planting between soil and artificial ground on surface level. Second, It is strongly recommended to integrate the whole planting base which involves architectural structure, drainage, and water proofing above the planting design. When considering that process as a professional subject dealing with natural material such as trees and shrubs, those tasks should be directed by landscape architectural divison and landscape architect. And planting area for artificial ground has to be specified in initial phase of architectural design. This step provides an opportunity to make a proper decision on structural load, drainage, and water proof design as an integrated part of the management.

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DOE를 적용한 카메라폰 모듈용 비구면 Glass렌즈의 성형조건 연구 ; 가압조건 (A Study on Molding Condition of Aspheric Glass Lenses for Mobile Phone Module Using Design of Experiments ; Pressing Condition)

  • 차두환;이준기;김상석;김혜정;김정호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.57-57
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    • 2007
  • Aspheric glass lenses have many optical advantages, for glass have superior optical performance and an aspheric form can reduce optical aberrations. Recently, the use of it is rapidly expanding as the mass production becomes possible by glass molding press and so this method is considered as the best method for fabricating an aspheric glass lens, but it is difficult to control many parameters for pressing and cooling process. Design of experiments (DOE) is a very useful tool to design and analyze complicated industrial design problems. This study investigated the pressing conditions to mold aspheric glass lenses for mega pixel phone camera module using DOE method. We have applied fractional factorial design and the response variable was set form accuracy (PV) of aspheric surface of molded lens. The results of analysis indicates that all factors expect for pressing force of each step are available for the form accuracy (PV). It was the optimum condition of the designed pressing conditions for lowering the form accuracy(PV) value of molded lens that all factors were at the low level. The form accuracy (PV) of mold and molded lens under the optimum condition are $0.85\;{\mu}m$ and $0.922\;{\mu}m$ respectively.

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N-methyl-N-nitro-N'-nitrosoguanidine의 변이원성에 대한 빈랑 물 추출물의 돌연변이 억제효과 (Desmutagenic Effect of Water Extract from Areca catechu L. on the Mutagenicity of N-Methyl-N-Nitro-N'-Nitrosoguanidinein in E. coli PQ37)

  • 오위걸;안병용
    • 한국약용작물학회지
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    • 제20권1호
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    • pp.16-19
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    • 2012
  • The desmutagenic activity of the water extract of Areca catechu L. on the mutagenicity induced by aflatoxin $B_1$ ($AFB_1$), N-methyl-N-nitro-N'-nitrosoguani-dine (MNNG), mitomycin C (MMC) and 4-nitroquinoline 1-oxide (4-NQO) was studied by using the SOS Chromotest with Escherichia coli PQ37. The inhibition rates of water extract of Areca catechu L. at concentration of $100{\mu}g/assay$ were 41.0%, 47%, 46%, and 32% against $AFB_1$, MNNG, MMC and 4-NQO, respectively. The water extract of Areca catechu L. was separated into methanol soluble and methanol insoluble parts. The methanol insoluble part exhibited higher inhibition effect than the methanol soluble part against the mutagenic activities of MNNG. Step-wise fractionation of methanol insoluble part was done to obtain methanol, ethyl acetate and water fractions. Among these fractions, water fraction had the strongest inhibitory effect of 45.0% against mutagenicities of MNNG. The inhibition rates of aqueous fraction of methanol-insoluble from water extracted Areca catechu L. at concentrations of 1.61, 16.13, 161.29 and $322.58{\mu}g/mL$ were 12.0%, 24.0%, 47.5% and 62.0%, respectively. The water fraction showed the inhibitory effects with dose response against the mutagenic activity induced by MNNG.

시험관내에서 천연물제제 BSASM의 항염증 및 면역억제 효능 평가 (Evaluation of the Anti-inflammatory and Immunomodulatory Effects of BSASM Using in vitro Experiments)

  • 이종성;박유미;박병화;정광선;김국현;이원희;박덕훈
    • 생약학회지
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    • 제34권3호통권134호
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    • pp.228-232
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    • 2003
  • For effective management of atopic dermatitis, it is important to introduce a therapeutic agent although having the fewest side effects, has the greatest anti- inflammatory effect. In the course of screening anti-inflammatory agents, we obtained BSASM composed of several plant extracts. This study was designed to investigate anti-inflammatory and immunomodulatory effects of BSASM. As a first step, $NF-{\kappa}B$ luciferase reporter assay was performed to know the involvement of BSASM in the production of proinflammatory cytokines because $NF-{\kappa}B$ element has been known to play a major role in expression of cytokine genes such as interleukin-8 (IL-8) or tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$. LPS (lipolysaccharide)-induced $NF-{\kappa}B$ activation was inhibited by BSASM. In addition, we found the fact that BSASM inhibits LPS-induced produced production of IL-8 and $TNF-{\alpha}$ proinflammatory cytokines, indicating BSASM has anti-inflammatory effect. In interleukin-2 (IL-2) luciferase reporter assay in Jurkat T cells, BSASM reduced PHA (Phytohemagglutinin)-induced IL-2 luciferase activity, suggesting the possibility that BSASM might also have an immunomodulatory function in T cell-mediated immune response. Based on these results, we suggest the possibility that BSASM can be introduced to improve symptom of immune-related skin diseases, namely, atopic dermatitis.

Detection of Food-Grade Hydrogen Peroxide by HRP-Biocomposite Modified Biosensors

  • Chang, Seung-Cheol
    • 한국식품위생안전성학회지
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    • 제32권6호
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    • pp.447-454
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    • 2017
  • 본 연구의 목적은 식품 제조 중 표백 및 살균에 사용되는 과산화수소($H_2O_2$)의 잔류 농도 검출에 활용 될 수 있는 유리탄소전극 기반의 바이오센서의 개발이다. 미국 FDA 및 국내 식품의학안전처 등 식품 용 과산화수소(food grade $H_2O_2$)는 국내외적으로 35% $H_2O_2$ 수용액으로 규정한다. 연구에서 개발한 바이오센서는 감응 물질로 사용된 horseradish peroxidase를 graphene oxide와 aniline과 함께 biocomposite를 형성시킨 후 중성 pH에서 본 연구에서 새롭게 개발된 전기화학적 증착법을 수행하여 개발되었다. 센서구조 및 특성 평가를 위하여 SEM, 순환 전압 전류법 등을 수행하였으며 본 연구에서 개발된 바이오센서는 $10-500{\mu}M$ 농도의 $H_2O_2$에 대하여 직선상의 농도 의존적인 반응을 나타내었으며 최저 검출 한계는 $0.12{\mu}M$으로 산출되었다. 본 연구에서 개발된 센서의 전략적 가치는 향후 오징어포, 건어물 등 널리 유통되는 식품 중에 함유된 식품용 $H_2O_2$ 미량을 현장에서 쉽게 분석 할 수 있어서 비용-효과적 측면에서 그 가치가 우수하다는 것을 제시한다.

장애인.노약자를 위한 응급상황지원시스템 설계 (A Study on the Emergency Support System for Disabled and Aged People)

  • 남두희;임관수
    • 한국ITS학회 논문지
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    • 제7권5호
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    • pp.170-179
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    • 2008
  • 한국은 2000년에 고령화 사회에 진입하여 노인인구증가에 따른 노동생산성 정하, 삶의 질 추구, 장애인 증가로 인한 사회 문제가 증가되고 있다. 그러나 정보통신기술의 발달로 고령자들의 이동뿐만 아니라 실내외 생활에 편의를 도모할 수 있게 되었다. 대표적인 서비스로 u-City를 들 수 있으나 국가 계획상에는 아직 구체적인 내용이 없는 상태 또는 부족한 실정이다. 서울시를 대상으로 고령자의 생활 복지를 담당하는 각 구청과 응급상황 처리를 담당하는 소방방재청의 고령자 지원 서비스를 조사한 결과 고령자의 기기에 대한 두려움, 통합서비스부족, 일부 상황에서만 제공되는 서비스 등의 문제점 및 요구사항을 파악하였다. 이러한 문제점을 해결하기 위해 응급상황이 발생해야 제공되던 서비스를 탈피하여 생활 전반에 걸친 검지-확인-조치-대응의 4단계 순환관리 서비스를 제시하였다. 또한 관리체계 및 통신체계를 제시하므로 향후 국가계획 및 시스템 구축 시 참조모델로 활용할 수 있다.

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굽힘시험시의 Mg/Al/STS 3층 클래드재의 변형 및 파단특성 분석 (Failure and Deformation Analyses of 3-ply Mg/Al/STS Clad-Metalin Bending)

  • 김인규;송준영;오기환;홍순익
    • 대한금속재료학회지
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    • 제50권5호
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    • pp.345-351
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    • 2012
  • A three-point bending test was performed on roll-bonded Mg/Al/STS clad-metal plates under two different testing conditions (Mg layer in tension, or STS in tension) and their mechanical response and fracture behavior were investigated. Bending strength was found to be greater under the condition of Mg layer in tension. Heat treatment at $200^{\circ}C$ increased the bending formability, suggesting the interfacial strength increased at $200^{\circ}C$. Under the condition of Mg in tension, the clad heat-treated at $300^{\circ}C$ and $400^{\circ}C$ fractured in two steps, with the first step associated with the interfacial fracture between Mg and Al, and the second the fracture of the Mg layer. STS/Al layers were found to be bent without complete fracture. Under the condition of STS in tension, the clad heat-treated at $300^{\circ}C$ and $400^{\circ}C$ exhibited a very small load drop at the displacement, which is similar to that of the first load drop associated with the interfacial fracture under the condition of Mg in tension. In this case, no interfacial cracks were found and the complete cut-through fracture of clad was observed at low temperature heat treatment conditions, suggesting excellent interfacial strength. When the heat treatment temperature was higher than $300^{\circ}C$, interfacial cracks were observed. The local stress condition and the position of the interface with respect to the surface were found to have a great influence on the fracture behaviors of clad metals.

고장물리 기반 수중 매설형 PBA에 대한 신뢰성 설계 연구 (Reliability Design Analysis for Underwater Buriend PBA Based on PoF)

  • 김지영;이기원;윤홍우;이승진;허준기;권형안
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제17권4호
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    • pp.280-288
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    • 2017
  • Purpose: PBA buried in underwater requires high reliability because of its mission critical characteristic and harsh operational environment during its life cycle. Therefore, various reliability improvement activities are necessary. The defect on PBA manufacturing process have been studied, as a result, many activities and standards have been presented. However, there are less studies regarding failure pattern on physical features based on design. In this paper, we studied a possible failure patten based on physical features that is related with manufacturing process of PBA. And reliability improvement design based on PoF (Physical of Failure) were intruduced in this paper. Methods: A reliability prediction simulation were performed on the components A and B of the H system using Sherlock Software which is a PoF commercial tool from DFR solution. Solder fatigue and PTH fatigue analysis based on thermal cycling profiles and random vibration was analyzed on three earthquake response spectrum. Result: It was validated that life time and reliability improvement design through solder fatigue and PTH fatigue analysis in case of component. For compoenet B, random vibration fatigue was additionally analyzed and validated reliability for earthquakes profile. Conclusion: In design stage prior to manufacturing, PoF can be analyzed, and it is possible to make a reliability improvement/validated design using design data. This study can be applied in every design step and contribute to make more stable development product.

새 구조의 액정 엑스선 감지기 (A New X-Ray Image Sensor Utilizing a Liquid Crystal Panel)

  • 노봉규
    • 한국광학회지
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    • 제19권4호
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    • pp.249-254
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    • 2008
  • 새 구조의 액정 엑스선 감지기를 만들었다. 이것은 액정판을 만들고 유리판을 얇게 식각한 다음, 그 유리판 위에 반사막과 광전도층을 연속하여 입힌 구조이다. 새 구조의 액정엑스선 감지기는 공정의 안정성, 대면적화, 감도 등에서 이미 상품화된 엑스선 감지기와도 충분히 경쟁할 수 있으며, 따라서 성공적으로 상용화 할 수 있음을 확인했다.