• Title/Summary/Keyword: Tightness

검색결과 438건 처리시간 0.032초

고속철도차량 갱웨이 벨로우즈의 비선형 해석 (Nonlinear Analysis of Rubber Bellows for the High Speed Railway Vehicle)

  • 강길현;김철수
    • 한국산학기술학회논문지
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    • 제14권8호
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    • pp.3631-3637
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    • 2013
  • 갱웨이 벨로우즈는 관절형 고속철도차량 객차 끝단부 사이에 다양한 변위차를 고려하여 갱웨이 프레임에 장착된 이중 주름구조 네오프렌 고무부품이다. 실제 운행중의 벨로우즈의 파손은 터널 통과시 기밀 파손으로 인한 이명현상 발생과 함께 소음 증가로 승객의 승차감에 심각한 영향을 미친다. 본 연구에서는 고속철도차량 갱웨이 벨로우즈의 안전성 연구일환으로서, 차량주행시 차량 끝단부의 3축 회전변위(롤링, 요잉, 피칭변위차)를 고려한 갱웨이 벨로우즈의 비선형 해석을 수행하였다. 본 고무의 비선형 재료 특성은 단축인장 및 등2축 인장시험을 수행하여 구하였다. 또한, 비선형 해석결과로부터 회전변위 및 마찰계수의 영향을 평가하였다.

통계적 최적화를 위한 확률적 글리치 예측 및 경로 균등화 방법 (Stochastic Glitch Estimation and Path Balancing for Statistical Optimization)

  • 신호순;김주호;이형우
    • 대한전자공학회논문지SD
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    • 제43권8호
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    • pp.35-43
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    • 2006
  • 이 논문에서는 공정 변이의 고려를 위한 통계적 시간 분석(statistical timing analysis)에서 전력감소를 고려한 회로의 최적화를 위해 글리치 및 지연시간의 확률적 모델 및 연산을 이용하여 각 경로 및 경로상의 게이트의 민감도(sensitivity)를 계산하고 이를 이용한 사이징(sizing)을 통해 회로의 지연시간의 증가 없이 글리치를 감소하는 방법을 제시한다. 제안된 알고리즘은 통계적 시간 분석에 근거한 회로의 전후방 탐색을 이용하여 공정 변수를 고려한 확률적 글리치 발생률을 예측한다. 또한 글리치 발생률을 고려한 게이트의 선택 및 사이징 가능한 지연시간의 최적화된 계산을 통해 효율적인 게이트 사이징 기법과 글리치 감소를 위한 경로균등화 방법을 제시한다. 제안된 알고리즘의 효율성은 $0.16{\mu}m$ 모델 파라미터를 이용하여 ISCAS85 벤치마크 회로에 대한 실험을 통해 검증되었다. 실험 결과를 통해 제안된 알고리즘은 글리치 예측에 있어 8.6%의 정확도의 개선을 보였고, 경로균등화에 의한 최적화에 있어 9.5%의 개선을 보였다.

슬링(Sling) 시스템을 이용한 경부 안정화 운동 (Cervical stabilization exercise using the Sling system)

  • 권재확;조미주;박민철;김선엽
    • 대한정형도수물리치료학회지
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    • 제8권2호
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    • pp.57-71
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    • 2002
  • Cervical pain is a rapid increase that is owing to a flexion-extension whiplash injury, unappropriated posture, chronical repetition injury from abdominal position of head and neck, excessive repeating work, chronical deficiency of excercise. Because of that is bring about muscle unbalance, tightness of cervical extensor muscle, weakness of cervical deep flexor muscles, instability of cervical region and reduction of proprioceptive sensor. Recent the role of muscle is more emphasized for preservation of sine stabilization. And cognition of integrated muscular system, importance for the operation and relation is increased to maintain stability of the motor system and pertinent function. Therefore we are going to introduce the sling exercise and stabilization exercise method for advanced efficient of cervical and upper limb and for the muscle strengthening to importance cervical stabilization through neurological program as control the reaction of cervical stabilization. Sling exercise therapy(SET) concept consists of a system of diagnosis and treatment. The system of diagnosis involves testing the muscle's tolerance through progressive loading in open and close kinetic chains. The SET system contains elements such as relaxation, increasing the range of movement, traction, training the stabilizing musculature, sensory-motor exercises, training in open and close kinetic chains, dynamic training of the mobilizing musculature, cardiovascular exercise, group exercise, personal exercise at home Sensory-motor training is an essential element of the SET concept. The emphasis is on closed kinetic chain exercise on an unstable surface, there by achieving optimum stimulation of the sensory-motor apparatus.

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주거용 건물의 개별 환기시스템 필요성에 관한 연구 (The Individual Heat-recovery ventilation system of Residential Buildings)

  • 신우철;이왕제;윤종호;백남춘
    • KIEAE Journal
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    • 제14권6호
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    • pp.99-104
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    • 2014
  • Recently supply of low energy house is increasing which can enhance energy efficiency and indoor environment comfort. Low energy house have to secure air tightness as well as thermal performance so house become high airtightness and inevitably need heat recovery ventilator to enhance indoor air quality. However, most of current ventilation systems are one-click, controlling the entire space so it causes increasing of heating load and fan power which makes it hard to save energy. Thus, Individual Control system is required which can achieve both enhancing indoor air quality and decreasing heating load and electric fan power. Thereby, in this study, we analyzed the correlation between ventilation and fan power through mock-up experiment and measured ventilation load under individual control system. As a result, under the condition of $24^{\circ}C$ of indoor temperature for 6 month(November to April) in Daejeon, ventilation load by fan speed was $10.9{\sim}19.6kWh/m^2{\cdot}a$ when operated 24 hours and $7.6{\sim}13.7kWh/m^2{\cdot}a$ when operated 12 hours in night time. In addition, it is possible to reduce at most 60% of ventilation load under the individual control system; measured ventilation load was $7.4kWh/m^2{\cdot}a$ when operated 24 hours, and $5.5kWh/m^2{\cdot}$ when operated 12 hours in night time.

The Energy Analysis and Evaluation of the NEO-Hanok

  • Han, Sang Hee;Park, So Yeon;Park, Hyo Soon
    • KIEAE Journal
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    • 제14권2호
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    • pp.77-86
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    • 2014
  • Plenty of efforts have been made in the traditional architecture of Korea, Hanok, to develop various elements such as restoration, the introduction of new design, and energy-saving while systemic setups on standard and evaluation of eco-friendly energy design of Hanok are lacking. If we evaluate energy performance based on current standards without reflecting unique features of Hanok on the system, Hanok will be included in the very low grade among the residential buildings being included in the approval system of eco-friendly architecture or the unique features will be modified and the burden of increased construction cost. Therefore, this study is to prepare the basic reference for the introductory evaluation system by evaluating the energy performance level of NEO-Hanok based on the current building energy rating system. The result for NEO-Hanok based on the building energy rating system, we propose the rating standard with scorecard elements of NEO-Hanok by considering the necessity of identity and standard for NEO-Hanok. As a result of infiltration test to check the tightness, it was measured as 10.81 times/h (50 ACH). As we switch from the main insulation for the wall from the glass wool 64k(0.035W/mk) to rigid polyurethane foam first class first unit (0.024W/mk), the result was slightly increased from the first demand quantity rating yield $249.8kWh/m^2{\cdot}yr$ to $235.0kWh/m^2{\cdot}yr$. Current certificate system is focused more on the heating load than the cooling load, it is disadvantageous for Hanok, which has less cooling energy consumption in summer. The rating result from the target building study is level 4.

사무용 건물에서 전열교환 환기시스템과 일반공조기의 냉방에너지 비교분석에 관한 연구 (A Comparative Analysis on Cooling Energy of Heat Recovery Ventilator and Air Handling Unit in the Office Building)

  • 장지훈;김현수;어진선;이승복;김병선
    • KIEAE Journal
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    • 제16권6호
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    • pp.123-128
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    • 2016
  • Purpose: In order to save the energy consumption of buildings, buildings have been constructed with high performance insulation or airtightness. However, high performance insulation or air tightness has led to a poor indoor air quality. Therefore, HRV(Heat Recovery Ventilator) has received attention to save the energy consumption and insure a good air quality. Because existing research is almost about the performance of HRV in residential buildings, This study analyzed the effect of HRV on cooling energy consumption in commercial office building. Method: This study was proceeded at commercial office building in In-cheon. In order to evaluate the energy consumption of HRV, this study proposed two methods: estimating energy consumption of the room installed AHU(Air Handling Unit) system; estimating energy consumption of the room installed HRV system. Therefore, comparison of two methods was proceeded to evaluate energy performance of each method. Result: As the result of comparison between rooms installed AHU and HRV, the experiment showed that energy consumption of the room installed HRV system is about 22% less than the room of AHU system. This conclusion is considered because the room installed HRV system have maintained temperature well at set point temperature $26^{\circ}C$.

중복 Z-성형술을 이용한 큐피드활의 교정 (SURGICAL CORRECTION OF A CUPID'S BOW USING A DOUBLE Z-PLASTY: REPORT OF A CASE)

  • 유선열;서일영
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제27권1호
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    • pp.66-70
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    • 2005
  • 이차 구순비성형술을 받고자 본과에 내원한 편측성 완전 구순구개열을 가진 29세 남자 환자에서 상방으로 반전된 큐피드활과 적순부의 휘파람 변형을 교정하기 위해 중복 Z-성형술을 시행하였다. 수술 후에 반전된 큐피드활이 정상적인 형태로 재건되고 휘파람 변형이 없어졌으며 상순의 긴장도가 완화되었다. 중복 Z-성형술시 적순부 내에서만 피판을 형성하므로 피부에는 새로운 반흔이 생기지 않아 심미적으로 만족스러웠고 상순결절은 더욱 볼록해 졌다. 수술 4년경과 후 큐피드활은 부드러운 곡선으로 좌우 대칭을 이루고 매우 자연스럽게 보였으며 장기적인 추적관찰 결과 양호한 결과를 보였다. 중복 Z-성형술은 반전된 큐피드활의 교정시 다른 수술방법에 비해 술식이 간단하고 주위조직 손상이 적으며 휘파람 변형의 교정도 가능한 좋은 방법이라고 사료된다.

Forehead reconstruction with a custom-made three-dimensional titanium implant in a Parry-Romberg syndrome patient

  • Kim, Jae Yoon;Jung, Bok Ki;Kim, Young Suk;Roh, Tai Suk;Yun, In Sik
    • 대한두개안면성형외과학회지
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    • 제19권2호
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    • pp.135-138
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    • 2018
  • Parry-Romberg syndrome is a rare neurocutaneous syndrome characterized by progressive shrinkage and degeneration of the tissues usually on only one side of the face. It is usually difficult to restore the facial contour due to skin tightness. In this case report, we report a forehead reconstruction with custom-made three-dimensional (3D) titanium implant of a Parry-Romberg syndrome patient who was treated with multiple fat grafts but had limited effect. A 36-year-old man presented with hemifacial atrophy. The disease progressed from 5 to 16 years old. The patient had alopecia on frontal scalp and received a surgery using tissue expander. The alopecia lesion was covered by expanded scalp flap done 22 years ago. Also, he was treated with fat grafts on depressed forehead 17 years ago. However, it did not work sufficiently, and there was noted depressed forehead. We planned to make 3D titanium implant to cover the depressed area (from the superior orbital rim to the vertex). During the operation, we confirmed that the custom-made 3D implant accurately fit for the depressed area without any dead spaces. Previously depressed forehead and glabella were elevated, and the forehead contour was improved cosmetically. A custom-made 3D titanium implant is widely used for skull reconstruction and bring good results. In our case, the depressed forehead of a Parry-Romberg syndrome patient was improved by a 3D titanium implant.

흑색의상의 조형성과 상징성에 관한 연구 (A Study on Formality and Symbolism in Black Dress)

  • 곽혜선;금기숙
    • 복식
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    • 제37권
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    • pp.231-252
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    • 1998
  • Since the costume directly express human mental and emotional status, colors of costume can be valuable data to grasp the spirit of the times. Black is noticeably used in modern fashion and the study for black costume is very useful to understand modern fashion. There-fore the study mainly approaches the black costume, finding its background of appearance and symbolism, reviews the symbolism and formality of black expressed in the field of paint-ing and design beyond the fashion, and compar-es to fashion. The study result of the thesis is as follows ; First, black as a color is a one to light other neighboring colors, while it is a static, con-tractible and outstandigly attractived color. Second, black color traditionally symbolizes death, earth, air, North and inferior level and in the painting, it symbolized death, despair, fantastic world and the expression of pent-up self, while cities have been symbolized in the black printing in modern times. In the design, black has appeared with the industrial society, which symbolizes functionality and modernity. Third, black in the fashion design was symbolized death, sternness simplicity, modernity, sex, resistance and so on. Death became conspicious by a religious factor since the old times, sternness was influenced by Spanish fashion in the 16th century, simplicity by Dutch fashion in the 17th century and modernity by Baudelaire dandyism and Chanel little black dress, while sex and resistance were urged to the modern times by teenage inferior culture and stickiness to sex. Fourth, the formative features of black costume prefer simplicity, tightness and bareness in form, and in material, usually used glancing materials changed by the effect of light, lace, see-through fabric and matte one with depth. As a result, the black color is summarized to symbol death, expression of self and modernity. It is not a color of emotion but of mentality and artificial one against nature. Black color in fashion gets a strong power to express self in the symbolic aspect and draws a higher attention on human body than the fashion itself. By these features, black costume will be continuously prefered in spite of changes of the fashion.

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Active monitoring of pipeline tapered thread connection based on time reversal using piezoceramic transducers

  • Hong, Xiaobin;Song, Gangbing;Ruan, Jiaobiao;Zhang, Zhimin;Wu, Sidong;Liu, Guixiong
    • Smart Structures and Systems
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    • 제18권4호
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    • pp.643-662
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    • 2016
  • The monitoring of structural integrity of pipeline tapered thread connections is of great significance in terms of safe operation in the industry. In order to detect effectively the loosening degree of tapered thread connection, an active sensing method using piezoceramic transducers was developed based on time reversal technique in this paper. As the piezoeramic transducers can be either as actuators or sensors to generate or detect stress waves, the energy transmission for tapered thread connection was analyzed. Subsequently, the detection principle for tapered thread connection based on time reversal was introduced. Finally, the inherent relationship between the contact area and tightness degree of tapered thread connection for the pipe structural model was investigated. Seven different contact area scenarios were tested. Each scenario was created by loosening connectors ranging from 3 turns to 4.5 turns in the right tapered threads when the contact area in the left tapered threads were 4.5 turns. The experiments were separately conducted with a highly noisy environment and various excitation signal amplitudes. The results show the focused peaks based on time reversal have the monotonously rising trend with the increase of the contact areas of tapered threads within an acceptable monitoring resolution for metal pipes. Compared with the energy method, the proposed time reversal based method to monitor tapered threads loosening demonstrates to be more robust in rejecting noise in Structural Health Monitoring (SHM) applications.