• 제목/요약/키워드: Roll Characteristics

검색결과 512건 처리시간 0.028초

실내장식물 인테리어마감재의 연소특성에 관한 연구 (A Study on Combustion Characteristics of Finishing Materials in Interior Decoration)

  • 조광현;이봉우;윤명오
    • 한국가스학회지
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    • 제23권4호
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    • pp.10-18
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    • 2019
  • 실내장식물 인테리어 마감재에 대한 연소특성과 위험성을 ISO 5660-1 기준의 콘칼로리미터 장비와 ISO-TR-9122기준 FT-IR장비로 시험하였다. 콘칼로리미터 시험결과 바닥마감재 중 타일카페트(FF3)가 총방출열량(THR)이 $74.6mj/m^2$로 가장 높아 위험도가 크고, 최대 열방출률(PHRR)은 타일카페트(FF1)가 $726kW/m^2$로 연소가 쉽게 나타났다. FT-IR시험결과 CO, $CO_2$ 비는 타일카페트 (FF2, FF3) 5.996, 5.171 PPM 보다 롤카페트(FF1)가 8.146 PPM 으로 높아 독성 위험성이 큰 카페트 임을 알 수 있었다. 벽마감재의 경우 MDF합판(WF3)가 총방출열량(THR) $86.7mj/m^2$, 위험도가 크고 최대 열방출률(PHRR) $384kW/m^2$으로 착화가 쉽고, 독성지수도 5.5로 높게 나타났다. CO, $CO_2$의 비는 1.340~8,596 PPM으로 재료에 따라 많은 차이가 있지만 폴리에스터섬유판(WF4)이 8,596PPM으로 독성이 가장 높았다.

Response of square tension leg platforms to hydrodynamic forces

  • Abou-Rayan, A.M.;Seleemah, Ayman A.;El-Gamal, Amr R.
    • Ocean Systems Engineering
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    • 제2권2호
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    • pp.115-135
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    • 2012
  • The very low natural frequencies of tension leg platforms (TLP's) have raised the concern about the significance of the action of hydrodynamic wave forces on the response of such platforms. In this paper, a numerical study using modified Morison equation was carried out in the time domain to investigate the influence of nonlinearities due to hydrodynamic forces and the coupling effect between surge, sway, heave, roll, pitch and yaw degrees of freedom on the dynamic behavior of TLP's. The stiffness of the TLP was derived from a combination of hydrostatic restoring forces and restoring forces due to cables and the nonlinear equations of motion were solved utilizing Newmark's beta integration scheme. The effect of wave characteristics such as wave period and wave height on the response of TLP's was evaluated. Only uni-directional waves in the surge direction was considered in the analysis. It was found that coupling between various degrees of freedom has insignificant effect on the displacement responses. Moreover, for short wave periods (i.e., less than 10 sec.), the surge response consisted of small amplitude oscillations about a displaced position that is significantly dependent on the wave height; whereas for longer wave periods, the surge response showed high amplitude oscillations about its original position. Also, for short wave periods, a higher mode contribution to the pitch response accompanied by period doubling appeared to take place. For long wave periods, (12.5 and 15 sec.), this higher mode contribution vanished after very few cycles.

이동질량장치와 부력엔진을 포함한 무인 수중글라이더의 동역학 모델링 및 운동성능 해석 (Dynamic Modeling and Motion Analysis of Unmanned Underwater Gliders with Mass Shifter Unit and Buoyancy Engine)

  • 김동희;이상섭;최형식;김준영;이신제;이용국
    • 한국해양공학회지
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    • 제28권5호
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    • pp.466-473
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    • 2014
  • Underwater gliders do not have any external propulsion systems that can generate and control their motion. Generally, underwater gliders would obtain a propulsive force through the lift force generated on the body by a fluid. Underwater gliders should be equipped with mechanisms that can induce heave and pitch motions. In this study, an inner movable and rotatable mass mechanism was proposed to generate the pitch and roll motions of an underwater glider. In addition, a buoyancy control unit was presented to adjust the displacement of the underwater glider. The buoyancy control unit could generate the heave motion of the underwater glider. In order to analyze the underwater dynamic behavior of this system, nonlinear 6-DOF dynamic equations that included mathematical models of the inner movable mass and buoyancy control unit were derived. Only kinematic characteristics such as the location of the inner movable mass and the piston position of the buoyancy control unit were considered because the velocities of these systems are very slow. The effectiveness of the proposed dynamic modeling was verified through sawtooth and spiraling motion simulations.

카타마란형 파워요트의 내항성능 추정에 관한 연구 (Performance Prediction on the Seakeeping Characteristics of a Catamaran Power Yacht)

  • 손창배;오우준;구윤경;김옥석;이경우
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2010년도 춘계학술대회
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    • pp.385-386
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    • 2010
  • 선박의 상하동요 및 종동요 간의 내항성능은 승객에게 피로감을 주며, 적재된 화물과 선체에 탑재된 재설비에 구조적 하중을 가져오게 된다. 이러한 점을 개선하기 위해 소형 카타마란 파워요트 설계시 해당 실적선 조사와 선저형상을 결정하여 선형을 설계하였다. 본 연구에서는 국내 연안의 해양환경에 대한 기초자료를 토대로 운동성능 해석조건을 선정하였다. 이를 통해 카타마란형 레저선박의 운동성능을 선속에 따라 고찰하였다. 파도와 선박의 만남각에 따른 내항성능을 추정하여, 파랑의 만남주파수에 대한 응답진폭비와 운동성능이 우수한 영역에 대해서 평가하였다.

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보건사업전담 공중보건의사 직무만족도 및 제도 개선방안 (A Study on job satisfaction and strategies to improve the system of Public Health Doctors in Charge of Community Health programmes)

  • 정헌재;조희숙;배상수
    • 보건행정학회지
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    • 제14권1호
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    • pp.1-23
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    • 2004
  • This study was carried out to investigate the activities and job satisfaction of public health doctors in charge of community health programmes. Subjects were 138 public health doctors charged with community health project, registered in the roll of public health doctors, made out by Central Supporting Team for the District Health Work in 2002. Data was obtained from Ninety-six public health doctors. The response rate was 70%. The survey was conducted from March to April in 2003 bye-mail. The items of the questionnaire consisted of general characteristics of participants, understanding of their activities, support system, job satisfaction, and suggestions to improve the system. Collected data was analyzed using PC-SPSS 10.1. Descriptive analysis, t-test, and ANOVA test were used. The results are as follows: Most of the respondents showed a low participation rate in community health services, but they agreed to the importance of their activities and the necessity to modify and improve the system. 70% of the respondents were dissatisfied with their jobs. The participation in health planning and programmes of health center, and the degree of acceptance of their opinion from health center workers were significantly related to their job satisfaction. The participation rate of the public health doctors having specialty, in community health services is higher than that of the others. In terms of the supports for system operation, the reflection of one's intention in job arrangement process, education and public relation of this system, and the administrative and financial supports made significant differences in the job satisfaction and the accomplishment of their duty. The respondents hoped that the administrative and financial supports for public health doctors in charge of community health programmes should be reinforced to motivate them. They also wanted that they could keep from being overloaded with clinical services. They favored to conduct home visit, community diagnosis, health planning, and health promotion programs as their appropriate activities. From these results, we suggest some strategies to motivate and empower the public health doctors in charge of community health programmes.

드리스 반 노튼 컬렉션 고찰 (2) - 1992년 S/S ~ 2014년 F/W 남성복을 중심으로 - (An Observation on Dries Van Noten's Collections (2) - Focus on Men's Collections from 1992 S/S to 2014 F/W -)

  • 박신미
    • 복식
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    • 제66권3호
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    • pp.51-74
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    • 2016
  • The purpose of this research is to analyze the relationship between the inspirations and designs of Dries Van Noten's Men's collections from 1992 S/S to 2014 F/W. The specific questions of this research are as follows: what are the important design features of the Dries Van Noten's Mixed collections from 1985 S/S to 1991 F/W? What are 'the roots of inspiration' of Dries Van Noten's Men's collections from 1992 S/S to 2014 F/W, and what are the aesthetic criterions of Noten's works? How can the roots of inspiration be categorized and what are its features? How did these roots of inspiration influence the Noten's designs? The paper is a reference of how ideas turn to practical works, and what the relationship between inspiration and design. Researchers utilized a qualitative research method providing a systematic review of the previous studies by analyzing the content. To conclude, roots of inspiration of Dries Van Noten's Men's collections can be classified into nine categories: 'Interpretation', 'Ethnic', 'Multiple Contents', 'Subculture', 'Region', 'Artist', 'Fashion Item', 'Sports', and 'New Trend'. Through the roots of inspiration, sensibility of Belgium, England, Italy, French chic, inquiry of ethnic, artist, sports, the neuter gender image, 1950's, 1960's & 1970's trend & style of street fashion, elegance for men, romanticism, zoot, rock 'n' roll, teddy boy, mods, punk, new romantic and 19th century's Anglo-Saxon style are extracted and applied to the designs through cross impact. The identity of Dries Van Noten's Men's collections are cross culture contents and harmony of the old generation and new generation.

규칙파 실험에 의한 수중터널의 거동 및 동수역학적 특성 고찰 (Investigation on the Behavioral and Hydrodynamic Characteristics of Submerged Floating Tunnel based on Regular Wave Experiments)

  • 오상호;박우선;장세철;김동현
    • 대한토목학회논문집
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    • 제33권5호
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    • pp.1887-1895
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    • 2013
  • 이 연구에서는 2차원 조파수조에서 수리모형실험을 실시하여 수중터널 모형의 수리학적, 구조적 성능을 고찰하였다. 수심 및 부력 대 자중비를 다양하게 변화시킨 조건에서 파고 및 주기가 서로 다른 규칙파를 조파하여 실험을 수행하였다. 실험 자료의 분석을 통해서 연직방향 및 횡방향 동요가 파고 및 주기에 따라 선형적으로 증가함을 확인하였다. 반면에, 회전 운동의 크기는 파고 및 주기가 설계파 정도로 커지지 않으면 별로 크게 나타나지 않았다. 마찬가지로, 계류장력 및 수중터널에 작용하는 파력도 파고 및 주기에 따라 선형적으로 증가하였다. 수심 및 부력 대 자중비의 변화와 관련해서는, 구조적 거동 및 수중터널에 작용하는 파력의 크기 모두 수심 증가 및 부력 대 자중비 감소에 따라서 전체적으로 감소하는 경향이 나타났다.

MR 댐퍼를 이용한 대형 버스 현가장치의 반능동 제어 (Semi-Active Control of a Suspension System with a MR Damper of a Large-sized Bus)

  • 윤호상;문일동;김재원;오재윤;이형원
    • 한국생산제조학회지
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    • 제21권4호
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    • pp.683-690
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    • 2012
  • In this work, the semi-active control of a large-sized bus suspension system with an MR damper was studied. An MR damper model that can aptly describe the hysteretic characteristics of an MR damper was adopted. Parameter values of the MR damper model were suitably modified by considering the maximum damping force of a passive damper used in the suspension system of a real large-sized bus. In addition, a fuzzy logic controller was developed for semi-active control of a suspension system with an MR damper. The vertical acceleration at the attachment point of the MR damper and the relative velocity between sprung and unsprung masses were used as input variables, while voltage was used as the output variable. Straight-ahead driving simulations were performed on a road with a random road profile and on a flat road with a bump. In straight-ahead driving simulations, the vertical acceleration and pitch angle were measured to compare the riding performance of a suspension system with a passive damper with that of a suspension with an MR damper. In addition, a single lane change simulation was performed. In the simulation, the lateral acceleration and roll angle were measured in order to compare the handling performance of a suspension system using a passive damper with that of a suspension system using an MR damper.

자기예압 공기베어링 스테이지의 3 자유도 운동오차 측정 및 능동 보정 (Measurement and Active Compensation for 3-DOF Motion Errors of an Air Bearing Stage with Magnetic Preloads)

  • 노승국;김수현;곽윤근;박천홍
    • 한국정밀공학회지
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    • 제26권2호
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    • pp.109-117
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    • 2009
  • This paper presents a linear air bearing stage with compensated motion errors by active control of preloads generated by magnetic actuators with combination of permanent and electromagnets. A 1-axis linear stage motorized with a linear motor with 240mm of travel range is built for verifying this design concept and tested its performances. The three motions of the table are controlled with four magnetic actuators driven by current amplifiers and a DSP based digital controller. Three motion errors were measured combined method with laser interferometer and two-probe method with $0.085{\mu}m$ of repeatability for straightness error. The measured motion errors were modeled as functions of the stage position, and compensation were carried out with feedforward control because the characteristics of the motion control with magnetic actuators are linear and independent for each degree-of-freedoms. As the results, the errors were reduced from $1.09{\mu}m$ to $0.11{\mu}m$ for the vertical motion, from 9.42 sec to 0.18 sec for the pitch motion and from 2.42 sec to 0.18 sec for roll motion.

테일러드 칼라의 생산업체용 패턴과 교육용 패턴의 비교연구 (Comparative study of productive pattern and educational pattern of tailored-collar)

  • 신장희;손희순
    • 패션비즈니스
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    • 제13권5호
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    • pp.37-44
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    • 2009
  • As the modern society has become highly industrialized and functionalized, the entry of women in public affairs has become brisk and extensive, and the studies of jackets which can satisfy the functions and designs for various activities have become important. Especially in the tailored collar which is the typical collar for female jackets, the studies such as scientific original form design, and design evaluation through analyzing functionality and sensitivity and others must be systematically carried out. In this study, therefore, the objective was placed in examining the actual state of the production of the tailored collar in the field of production first, and inquiring the general theories on the constituent elements of tailored-collar and production methods by analyzing it and comparing it with the educational tailored-collar production methods. First, in regard to the relation between the collar and the length of the backside neck of the bodice, in most cases, they were employing the method to enlarge the length of the backside neck of the bodice by shortening the length of the neck-base girth. That is, they were processing in order that the self collar band inside of the roll line and the fall of the collar can make a soft curved line. Second, when producing tailored-collar patterns, it is desirable to very the inclination according to the breath of the collar or thickness of the fabric because the stability of the inclination of the collar differs depending on the condition the collar is set, the girth of the collar edge. the broader the breath of the collar becomes, the thicker the fabric becomes, and the more the cloth is against the cold, it is necessary to make the inclination larger. Third, in the size relation between the upper collar and under collar, when sewing collars, it becomes thick and stabilized as it goes from the part in which extra pieces were put to the part in which extra pieces are not put. So you must make the upper collar larger by putting in extra pieces. The amount to be put in differs depending on characteristics of the materials.