• 제목/요약/키워드: 강제효과

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크랭크축-실린더블록 계의 진동해석

  • 오성환
    • Journal of the KSME
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    • 제25권5호
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    • pp.406-412
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    • 1985
  • 연소 동안에 크랭크 축은 오일 필름을 통하여 연소압력이 실린더 블록으로 전달된다. 점화 전에 관성력에 의한 크랭크 축의 굽힘 변형은 크랭크 축으로부터 메인 베어링까지의 연소하중 전달에 큰 영향을 미친다. 메인 베어링에 베어링 보를 부착시키거나 크랭크 축의 굽힘 강성을 변화시켜 실린더 블록의 스커어트 진동을 감소시키는 효과를 얻었다. 크랭크 축의 비틂 진 동을 일으키는 회전력과 관성력 변동의 합력은 크랭크 저어널의 횡진동을 일으킨다. 크랭크 축의 횡 강제진동은 베어링 1에서 최대값이기 때문에 실린더 블록의 굽힘, 비듦 진동에 대하여 기진력이 된다. 실린더 블록의 진동 진폭은 관성력 변동의 주파수가 실린더 블록의 공진진 동수에 가까워지는 정도와 크랭크 축 비듦 진동의 진폭에 의존한다. 크랭크 풀리의 극관성 모우멘트와 크랭크 축 비듦 진동을 감소시키는데 효과를 준다.

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Investigation of Aerosol Optical Depth Retreived from GMS-5 During ACE-Asia 2001 : Case Study of Asian Dust Period (2001 ACE-Asia 기간동안에 관측된 GMS-5 위성에서의 에어러솔 광학두께: 황사사례를 중심으로)

  • 이권호;홍천상;김정은;류성윤;김영준;최병철;김지영
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 한국대기환경학회 2002년도 추계학술대회 논문집
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    • pp.442-443
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    • 2002
  • 인공위성에 의한 대기 에어러솔의 관측방법은 에어러솔이 기후에 미치는 영향의 평가에 있어서 중요한 요소가 되었다. 기본적으로 인공위성 원격탐사자료는 가시광선 영역역대의 밴드에서 대기중의 분자들이나 에어러솔에 의한 산란효과에 의해 영향을 받는다. 황사 현상과 같은 먼지구름은 인공위성 영상에서 쉽게 보이며 이러한 먼지 구름이 복사 강제 효과에 대한 기여도가 클 것으로 예측된다. (중략)

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An Exprimental Study on the Heat Transfer Performance in a Fluidized Bed Double Pipe Heat Exchanger (수직이중관식(垂直二重管式) 유동층형(流動層形) 열교환기(熱交換器)의 전열성능(傳熱性能)에 관한 실험적(實驗的) 연구(硏究))

  • Yoo, Ji-Oh;Seo, Jeong-Yun
    • Solar Energy
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    • 제14권2호
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    • pp.39-50
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    • 1994
  • Experiments have been conducted to measure the heat transfer coefficient and pressure drop in fluidized bed double pope heat exchangers with smooth tube and longitudinal finned tube. The effect of particle size(alumina beads; do=0.41, 0.54, 0.65, 0.77 mm) and static bed height on the heat transfer coefficient has been evaluated in terms of pumping power. The heat transfer coefficient for the smooth tube and finned tube heat exchangers has been compared with single phase double pipe heat exchanger. Results show that the heat transfer coefficients for the finned tube in $2.96{\sim}3.45$ times higher than the smooth tube. The heat transfer coefficients for the fluidized bed heat exchanger is higher than the single phase heat exchanger for the most of pumping power range tested. The maximum increase in the heat transfer coefficient for fluidized bed is 91.3% for the smooth tube and 127.1% for the finned tube.

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The Role of Central Postsynaptic ${\alpha}_2$-Adrenoceptor on the Immobility Duration in the Forced-swimming Test Mice (새앙쥐 강제수영시 부동자세 시간에 대한 Central postsynaptic ${\alpha}_2$-Adrenoceptor의 역할에 대한 연구)

  • Rhim, Byung-Yong;Kim, Sang-Kon;Lee, Won-Suk;Hong, Ki-Whan
    • The Korean Journal of Pharmacology
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    • 제21권2호
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    • pp.90-98
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    • 1985
  • 1) In the study of the forced-swimming test in mice (FSM), the duration of immobility posture was dose-dependently shortened by ${\alpha}_2$-agonists, clonidine and guanabenz. BH-T 933 and oxymetazoline also decreased it . Xylazine rather increased the immobility duration at low dose. 2) ${\alpha}_1$-Agonists, cirazoline, amidephrine and methoxamine, however, showed inconsistent effect on the immobility duration (ID). 3) The decrease in ID by clonidine and guanabenz was antagonized by pretreatment with yohimbine, idazoxan and phentolamine (${\alpha}_2$antagonist), but not by prazosin and corynanthine (${\alpha}_1$-antagonist) .4) The ID in the FSM was shortened dose-dependently by d-amphetamine, and it was also antagonized by yohimbine, but not by prazosin. 5) In the mice pretreated with either ${\alpha}$-methyl-p-tyrosine or reserpine, or with combination of both, the decrease in ID was still evoked by clonidine. 6) When the mice were chronically treated with antidepressants (desipramine and imipramine), or with electroconvulsive shock, clonidine still decreased the ID as it did in the control. 7) These results provided the evidences to hypothesize that the change of the ID in the FSM is closely related with the postsynaptie ${\alpha}_2$-adrenoceptor located on the central noradrenergic neuron body. Furthermore, it is assumed that this escape-directed behavior enhanced by ${\alpha}_2$-adrenoceptor agonist may be the result in some analogy with the incentive of drives which are directed toward the self-preservation.

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Online Survey on Clinical Application of Constraint-Induced Movement Therapy in Children with Hemiplegic Cerebral Palsy in Korea (편마비 뇌성마비 환아에서 강제유도운동치료의 국내 임상적용에 대한 설문조사)

  • Son, Ju-Hyun;Shin, Yong-Beom;Yun, Young-Ju;Kim, Bu-Young;Moon, Jung-In;Moon, Myung-Hoon;Kim, Soo-Yeon
    • The Journal of Korean society of community based occupational therapy
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    • 제9권2호
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    • pp.33-42
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    • 2019
  • Objective : The aim of this study was to evaluate the current knowledge regarding constraint-induced movement therapy (CIMT) and its application in clinical practice by physiatrists and therapists in pediatric rehabilitation area in Korea. Methods : Online survey via E-mails was sent to a total of 510 members (204 physiatrists and 306 therapists) of the Korean Society of Pediatric Rehabilitation and Developmental Medicine (KSPRDM). Results : The response rate was 35.1% (179 of 510). A total of 179 questionnaires was completed by 39 physiatrists, 89 physiotherapists, 48 occupational therapists, and 3 speech therapists. 45.8% of responders had worked over 6 years in the pediatric rehabilitation setting and a total of 58.1% (n=104) of the sample had used CIMT. The main limitations of clinically applying CIMT included limited staff and inappropriate clinical setting (35.1%, n=61), lack of understanding (19.5%, n=34), and developmental issues of function on the unaffected side (13.8%, n=24). The cooperation of patients (77.6%, n=76), cognitive/behavioral factors (42.9%, n=42), and cooperation of caregivers (25.5%, n=25) were the 3 major concerns that could be limitations with CIMT. Conclusions : Although considerable evidence supports the use of CIMT, many of physiatrist and therapists do not apply this method in practice. The improvement of limitations is necessary for wide use of CIMT in clinical practice in Korea.

Wilted Symptom in Watermelon Plant under Ventilation Systems (환기처리에 의한 수박의 시듦증 발생 기작)

  • Cho, Ill-Hwan;Ann, Joong-Hoon;Lee, Woo-Moon;Moon, Ji-Hye;Lee, Joo-Hyun;Choi, Byung-Soon;Son, Seon-Hye;Choi, Eun-Young;Lee, Sang-Gyu;Woo, Young-Hoe
    • Horticultural Science & Technology
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    • 제28권4호
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    • pp.529-534
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    • 2010
  • Occurrence of wilted symptom in watermelon plant ($Citrullus$ $lanatus$ L.) is known to be caused by physiological disorder. The symptom results in the loss of fruit production and thus the economical loss of watermelon growers. The incidence of symptom is often found from the middle of March to the end of May in the major watermelon crop production areas of Korea (i.e. Uiryeong, Gyeongnam (lat $37^{\circ}$56'64"N, long $126^{\circ}$99'97"E)). Despite of extensive information about the physiological disorder, little study has been conducted to understand a relationship between the wilted symptom and accompanying environment factors (e.g. temperature). This study aimed to investigate effects of environmental conditions amended by a forced-ventilation system on physiological characteristics of watermelon and incidence of the wilted symptom. Watermelon plants were grown from January to May, 2009 with either the forced-or natural-ventilation treatment in a greenhouse located in the Uiryeong. In the result, the forced-ventilation treatment decreased the air, leaf and root-zone temperature approximately $4.5^{\circ}C$, $5^{\circ}C$ and $3^{\circ}C$, respectively, compared to the natural-ventilation. The fruit growth rate was maximized twice during the entire growing period. The higher rate of fruit growth was observed under the natural-ventilation than the forced one. Maximization of the fruit growth rate (approximately 430 g per day) was first observed by 12 days after fruiting under the natural-ventilation treatment, while the second one (approximately 350 g per day) was observed by 24 days after fruiting. The wilted symptom started occurring by 22 days after fruiting under the natural-ventilation, whereas no incidence of the symptom was found under the forced-ventilation treatment. Interestingly, the forced-ventilation lowered the fruit growth rate (approximately 320 g per day) compared to the natural one. Maximization of the fruit growth rate under the forced-ventilation was found at 4 days later than that under the natural one. This result coincided with a slower plant growth under the forced-ventilation treatment. These results suggest that the forced-ventilation slows down extension growth of fruit and plant, which may be associated with lowering leaf temperature and saturation deficit. We suggest the hypothesis that the forced-ventilation may alleviate stress of the wilted symptom by avoiding extreme water evaporation from leaves due to high temperature and thus by reducing competition between leaves and fruits for water. More direct and detailed investigations are needed to confirm the effect of the forced ventilation.

A Study on the Enhancement of Maritime Education and Training to cope with IMO Member-state Audit Scheme (IMO 회원국 감사제도 대응을 위한 해기교육 강화방안에 관한 연구)

  • Lee, Yun-Cheol;Park, Sung-Ho
    • Journal of Navigation and Port Research
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    • 제37권2호
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    • pp.203-210
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    • 2013
  • In spite of adoption of various IMO Conventions over the past, the reason why large vessel accidents related to human life and marine environment occur is that the IMO Conventions are not effectively implemented due to contravention of the conventions by flag states. In particular, the implementation of the conventions are not well being performed because some flag states having weak genuine link between them and vessels haven't set up proper personal and structural organizations in charge of maritime safety and marine environment protection. From this background, IMO Resolution A.946(23) on the voluntary IMO Member-state Audit Scheme was adopted at the 23rd Assembly in Nov. 2003 and the Scheme is expected to be executed compulsorily in 2015 through the adoption of the IMO Resolution A.1018(26) in Nov. 2009. Accordingly, this study examined outline of the IMO Member-state Audit Scheme and the Code for the Implementation of Mandatory IMO Instruments used for the audit standards of this scheme. In addition, this study reviewed the member-states' obligations and responsibilities according to the compulsory implementation of the member-state audit scheme in 2015. Based on this, this study suggested the enhancement measures for maritime education and training of maritime education institutions of the Republic of Korea to cope positively with compulsory implementation of the IMO Member-state Audit Scheme.

Antifatigue Effect of Chlorella vulgaris in Mice (클로렐라의 항 피로 효과 연구)

  • An Hyo-Jin;Seo Sang-Wan;Sim Kyung-Sik;Kim Jung-Suk;Kim Eun-Hee;Lee Mi-Ok;Park Hyeung-Suk;Han Jae-Gab;Lee Eun-Hee;Um Jae-Young;Hong Seung-Heon;Kim Hyung-Min
    • The Korean Journal of Food And Nutrition
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    • 제19권2호
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    • pp.169-175
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    • 2006
  • A unicellular algae, Chlorella vulgaris(CV), was used as a biological response modifier. The effect of CV on forced swimming test and blood biochemical parameters related to fatigue was investigated. Blood urea nitrogen(BUN); creatine kinase(CK); lactic dehydrogenase(LDH); glucose(Glc); total protein(TP); and albumin were determined. CV was orally administered to mice in the range of 0.05 to 0.15 g/kg/day. A forced swimming test results on 3 and 7 day after administration of CV, showed that immobility time was decreased in the CV-administered group(0.15 g/kg). In addition, the contents of BUN in the blood serum were decreased in CV-fed group. The contents of CK and LDH were tended to decrease, but not statistically significant. The plasma Glc level was increased in CV-fed groups(0.05 and 0.1 g/kg) compared to control group. It had no effect on the elevation of TP and albumin level. The results indicate that CV could improve physical stamina.

Survey on the Use and Awareness of Nail Convergent Strengtheners (네일 융복합보강제의 사용실태 및 인식도 조사)

  • Kim, Mi-Won;Back, Dae-Jin
    • Journal of Digital Convergence
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    • 제13권8호
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    • pp.535-542
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    • 2015
  • As the nail industry has grown, concerns on damages to natural nails due to nail services and interests on nail products have been increased. This study is on nail convergent strengtheners which reduce damages on natural nails, and especially focused on the use and awareness of nail strengtheners by nail technicians. First, documentary research on previous studies was conducted to define nail services, nail damages, and nail strengtheners. Preliminary survey and main survey was conducted by KSDC on-line survey tool and the result was analyzed by frequency analysis, cross analysis, and correlation analysis by KSDC advanced statistical program. As a result, nail technicians have the high level of awareness on characteristics, effects, how to use, and application process of nail strengtheners. Nail technicians are the mid level of awareness on the ingredients of nail strengtheners.

The Effects of Task Oriented Activity and Modified Constraint Induced Movement Therapy on Quality of Life for Patients With Stroke (과제 지향적 훈련과 수정된 강제유도 운동치료가 뇌졸중 환자의 삶의 질에 미치는 영향)

  • Lee, Jong-Min;Kim, Bo-Ra
    • Therapeutic Science for Rehabilitation
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    • 제1권2호
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    • pp.23-34
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    • 2012
  • Objective : The purpose of this study was to investigate the effect of task oriented activity and modified constraint induced movement therapy (mCIMT) on Quality of Life (QOL) for patients with stroke. Methods : Thirty stroke patients were participated voluntarily and were assigned randomly into task oriented activity and mCIMT groups. The QOL of both groups were assessed using Stroke Specific Quality of Life (SS-QOL). Results : The QOL showed a statistically meaningful difference for both groups (p<.05), but after the intervention, the both groups showed no statistically meaningful difference in terms of the QOL (p>.05). Conclusion : We found that task oriented activity and mCIMT improve the QOL of patients with stroke through increasing their affected upper extremity function and movement. It is expected that task oriented activity and mCIMT will have a positive effect on the QOL of stroke patients by applying them to clinic with occupational therapy.