• 제목/요약/키워드: first passage

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정치망 어구어법의 개발에 관한 연구-I - 현용어구의 흐름에 대한 형상 변화 - (A Study on Improvement for Fishing Gear and Method of Pound Net - I - Net Shapes of the Commerical Net in the Flow -)

  • 윤일부;이주희;권병국;조영복;유제범;김성훈;김부영
    • 수산해양기술연구
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    • 제40권4호
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    • pp.268-281
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    • 2004
  • 본 연구는 실제 정치망 어장에서의 조류에 따른 어구 형상 변형을 추정하고, 그 변형을 최소화시키며 어구의 기본 기능을 유지시키는데 필요한 수중 현상과 어구 내부용적을 적절하게 유지할 수 있는 설계의 기본 자료를 얻기 위한 목적으로 회류 수조에서 모형실험을 실시하였으며, 흐름에 따른 대뜸의 멍줄에 작용하는 장력, 정치망 내의 유속변화와 그물형상의 변화를 측정하였다. 1. 유속이 0.0m/s에서 0.6m/s로 증가 할 때에 유속 (v)에 따른 장력(R)의 실험식은 운동장 조상의 경우 R=$19.58v^{1.98}$($r^2$=0.98) 원통 조상인 경우, R=$26.90v^{1.72}$($r^2$=0.95)이었다. 2. 유속변화는 흐름이 망내부를 통과함에 따라 감소하여 운동장이 조상인 경우, 제1원통내부에서 0.1m/s일 때 약 70%, 0.2m/s일 때 60%, 0.3m/s일 때 약 50%, 0.4~0.6m/s에서는 약 40%정도로 초기유속에 비해 감소하였다. 원통이 조상측일 경우, 제2원통을 통과한 흐름은 초기 유속의 약 30~60%로 급격히 감소하였고, 제1원통에서는 약 20~30% 비탈그물에서는 약 10~20%정도 감소하였고, 운동장내에서 다시 유속이 증가하였다. 3. 운동장이 흐름의 조상측인 경우, 운동장그물의 기울기 변화량은 0~70$^{\circ}$까지, 비탈그물은 0~63$^{\circ}$까지 변화하였고, 조하측인 제2원통은 0~47$^{\circ}$까지 변화하였다. 유속이 증가함에 따른 까래그물의 깊이 변화는 초기 깊이에 보다 제1원통과 제2원통이 약 0~45%정도, 비탈그물이 약 0~37% 정도로 감소하였다. 4. 원통이 흐름의 조상측인 경우, 제2원통의 기울기 변화량은 약 0~70$^{\circ}$까지, 비탈그물은 약 0~55$^{\circ}$까지, 조하측인 운동장은 0~50$^{\circ}$까지 였다. 까래그물의 깊이 변화는 초기 깊이와 비교해서 제1원통은 약 0~35%, 제2원통은 약 0~20%, 비탈그물은 약 0~35%까지 감소하였으며, 유속이 0.5m/s이상에서 비탈그물이 원통 입구까지 부상하여, 원통 입구를 90%이상 막았다. 5. 어구의 변형을 최소화하고 전개용적을 증가시키기 위해서는 입구 및 운동장 부분에서는 힘출의 저조시 수심 위치에 중량추를 부착하고, 운동장 바깥쪽과 제1원통의 섶장과 까래그물 제2원통의 바깥쪽, 비탈그물의 까래에 부가 중량추를 부착하는 것이 필요할 것으로 판단된다.

회전하는 냉각유로의 곡관부에 부착된 가이드 베인의 형상 최적설계 (Shape Optimization of a Rotating Two-Pass Duct with a Guide Vane in the Turning Region)

  • 문미애;김광용
    • 한국유체기계학회 논문집
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    • 제14권1호
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    • pp.66-76
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    • 2011
  • The heat transfer and pressure loss characteristics of a rotating two-pass channel with a guide vane in the turning region have been studied using three-dimensional Reynolds-averaged Navier-Stokes (RANS) analysis, and the shape of the guide vane has been optimized using surrogate modeling optimization technique. For the optimization, thickness, location and angle of the guide vanes have been selected as design variables. The objective function has been defined as a linear combination of the heat transfer and the friction loss related terms with a weighting factor. Latin hypercube sampling has been applied to determine the design points as design of experiments. A weighted-average surrogate model, PBA has been used as the surrogate model. The guide vane in the turning region does not influence the heat transfer in the first passage upstream of the turning region, but enhances largely the heat transfer in the turning region and the second passage. In an example of the optimization, the objective function has been increased by 13.6%.

Factors Affecting Primary Cultures of Abalone Haliotis discus hannai Ovary-dissociated Cells and General Culture Aspects

  • Ryu, Jun Hyung;Nam, Yoon Kwon;Gong, Seung Pyo
    • Fisheries and Aquatic Sciences
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    • 제18권1호
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    • pp.81-88
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    • 2015
  • We investigated factors affecting primary cultures of Pacific abalone Haliotis discus hannai ovary-dissociated cells to identify general aspects of their early-phase culture. Ninety-seven cell populations derived from 30 individuals were cultured in different media with varying compositions of medium supplements, and initial attachment, subculture, and survival for ${\geq}10$ weeks were assessed according to medium composition and individual. We also examined the time required for subculture and the rate of cell death according to both culturing period and passage number within 10 weeks. A lack of fetal bovine serum (FBS) and hemolymph significantly inhibited the growth of cultured cells, while we detected no significant effect of medium composition on initial cell attachment. Through data reallocation, with the omission of data from cell populations cultured in FBS-free and hemolymph-free media, we showed that growth inhibition was also affected by individual differences among the abalones used. During the culture, we observed four different types of cell morphology. Moreover, considerable time was required for subculture-18.4 and 19.5 days for first and second subcultures, respectively-and cell death did not occur within 30 days or for passage 0. Our results will provide valuable information for developing universal cell culturing guidelines in abalone species and suggest the feasibility of culturing abalone ovary-dissociated cells.

A Study on the Flow Field Characteristics of Air Induction System for Reducing the Signal-to-Noise in the MAFS Output

  • 유성출
    • 한국분무공학회지
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    • 제5권1호
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    • pp.49-57
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    • 2000
  • This study presents the flow visualization results, velocity and turbulence intensity measurements made within an air filter cover and entry region of a mass air flow sensor (MAFS) which is used in an induction system of 3.8L engine. Flow structure in two air filter cover assemblies were examined. The first was a clear plastic replica of the production cover while the second was a modified clear plastic cover with a geometry configured to reduce fluctuations. High speed flow visualization and laser doppler velocimetry (LDV) systems were used to reveal and analyze the flow field characteristics encountered in the sensor design process under steady flow conditions. A 40-watt copper vapor laser was used as a light source. Its beam is focused down to a sheet of light approximately 1.5mm thick. The light scattered off the particles was recorded by a 16mm high speed rotating prism camera at 5000 frames per second. A comparison of the flow patterns and LDV measurements in the original and modified air filter covers is presented to illustrate the controlling effect of the cover design on the turbulence structure formation near the bypass and on the sensor output signal. In both axial and radial planes of the main passage it was found that the turbulence flow pattern is remarkably influenced by the air filter cover and main passage configuration.

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파킨슨 환자의 클리어 스피치 전후 음향학적 공기역학적 특성 (An aerodynamic and acoustic characteristics of Clear Speech in patients with Parkinson's disease)

  • 신희백;고도홍
    • 말소리와 음성과학
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    • 제9권3호
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    • pp.67-74
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    • 2017
  • An increase in speech intelligibility has been found in Clear Speech compared to conversational speech. Clear Speech is defined by decreased articulation rates and increased frequency and length of pauses. The objective of the present study was to investigate improvement in immediate speech intelligibility in 10 patients with Parkinson's disease (age range: 46 to 75 years) using Clear Speech. This experiment has been performed using the Phonatory Aerodynamic System 6600 after the participants read the first sentence of a Sanchaek passage and the "List for Adults 1" in the Sentence Recognition Test (SRT) using casual speech and Clear Speech. Acoustic and aerodynamic parameters that affect speech intelligibility were measured, including mean F0, F0 range, intensity, speaking rate, mean airflow rate, and respiratory rate. In the Sanchaek passage, use of Clear Speech resulted in significant differences in mean F0, F0 range, speaking rate, and respiratory rate, compared with the use of casual speech. In the SRT list, significant differences were seen in mean F0, F0 range, and speaking rate. Based on these findings, it is claimed that speech intelligibility can be affected by adjusting breathing and tone in Clear Speech. Future studies should identify the benefits of Clear Speech through auditory-perceptual studies and evaluate programs that use Clear Speech to increase intelligibility.

농어촌 장애인 주택의 개조방안 연구 -지체장애인 및 뇌병변장애인 거주주택을 중심으로- (A Study on Improvement of Rural Housing for the Disabled - Focus on the Housing Where Live in Physically Disabled and Persons with Brain Resions -)

  • 이규일;정광호
    • 한국디지털건축인테리어학회논문집
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    • 제12권4호
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    • pp.39-48
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    • 2012
  • Generally, rural housing in Korea have had target of people who are in good physical health rather than the disabled. Therefore, it is difficult to offer high quality residential environment for the elderly and the disabled. The purpose of this study is to present the remodeling of rural house for the disabled. this study divides the a rural house into 7 sectors : a passage to entrance, an entrance hall, a livingroom, a bedroom, a bathroom, a kitchen, and etc. this study propose the following renovation plan that rural housing to be barrier free space. First, in passage to entrance of the house, people with disabilities should not experience difficulties in walking, so installing ramps to remove the stepped slope grade without slip so that the floor finish should be. Second, install grab handle on the wall inside the housing so that the disabled can lean on the handle. Third, placing the furniture in the bedroom that wheelchair can be rotated, and make to lower the height of the switchs. Forth, install a non-slip floor tile to prevent accidents in the bathroom.

편측 상악동 저형성증의 진단과 치료 (Diagnosis and Treatment of Unilateral Maxillary Sinus Hypoplasia)

  • 김성민;김민근;권광준;이석근;박영욱
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제34권2호
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    • pp.127-132
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    • 2012
  • Maxillary sinus hypoplasia (MSH) is an uncommon clinical disease that represents a persistent decrease in sinus volume, which results from centripetal reaction of the maxillary sinus walls. We present a unilateral MSH case of a 46-year-old male patient with a history of nasal obstruction and headache for 3 years. He had a history of Caldwell Luc operation (CLOP) 10 years ago, and no enophthalmos, hypoglobus or facial asymmetry. After confirming the right diagnosis of MSH, filled with bone in the computed tomography scan, hyperplastic bone was removed by the CLOP approach. The uncinate process and infundibular passage were found to be degenerated and ostium was also examined to be obstructed under endoscopic confirmation. MSH can be mistaken for chronic maxillary sinusitis because of the plain x-ray appearance, so the aggravated state of MSH can be the result of surgeon's misjudgment. With additional literature reviews, this rare experience is first introduced in our Korean oral and maxillofacial surgery field.

비후성 비염환자에서 음성검사 및 음향비강통기도검사를 이용한 수술전후 비교 (Postoperative Change in Hypertrophic Rhinitis(Study Using Nasometer, CSL and Acoustic Rhinometer))

  • 유영삼;우훈영;윤자복;최정환;조경래
    • 대한후두음성언어의학회지
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    • 제12권1호
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    • pp.34-38
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    • 2001
  • Background and Objectives : With the development of computerized systems, an objective evaluation methods of nasal speech and nasal geometry have become readily available by means of a simple, noninvasive technique. In this study, we assessed the nasality, nasal formant, nasal volume and nasal area in patients with hypertrophic rhinitis before and after turbinate surgery. Material and Method : With the nasometer, we measured nasalance, which reflects the ratio of acoustic energy output of nasal sounds from the nasal and oral cavities. With CSL 4300B, we measured nasal formants. We used acoustic rhinometer to measure nasal area and nasal volume. Postoperative changes of above factors were compared with preoperative values. Paired t-test and Pearson's correlation were used for statistical analysis. Results : The first nasal formant frequency, nasalance scores of three passages(baby, mamma and rabbit passages), minimal cross sectional area(MCA) of narrow side, nasal volume of narrow side and nasal volume of wide side had increased significantly after turbinate surgery (p <0.05). The MCA and nasal volume of narrow side and MCA of wide side showed significant correlation with nasalance score of rabbit passage and baby passage showed significant correlation with nasal volume of narrow side(p<0.05). Conclusion : There were significant increases in nasalance scores, first nasal formant frequency, MCA and nasal volume after turbinate surgery. Thus, we must consider the possibility of voice changes postoperatively in professional voice users.

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식도 및 기도이물의 임상통계학적 고찰 (A Statistical Analysis of the Fereign Bodies in the Food and air Passages)

  • 정해영;권평중;박성준;민양기;김중환
    • 대한기관식도과학회:학술대회논문집
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    • 대한기관식도과학회 1978년도 제12차 학술대회연제 순서 및 초록
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    • pp.4.1-4
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    • 1978
  • 식도 및 기도이물은 이비인후과 영역에서 자주 볼 수 있는 질환이며 특히 기도이물은 단시간내에 치명적일 경우가 있으므로 이비인후과 영역에서 매우 중요하다고 하겠다. 저자들은 1968년 6월부터 1978년 4월까지 최근 9년10개월간 본원에 내원하였던 95례의 식도 및 기도이들 환자들을 임상통계학적으로 분석하여 다음과 같은 결과를 얻었기에 문헌고찰과 함께 보고하는 바이다. 1. 식도 및 기도이물관자는 총 95례로서 식도이물이 89례(93.7%), 기도이물이 6례(6.3%)였으며 그 비는 14.8 : 1이었다. 2. 성별비에서는 64례(67.4%)가 남자였고, 31례(32.6%)가 여자로서 그 비는 2. 1 : 1이었다 3. 식도 및 기도이물을 종류별로 보면 식도이물에서는 주화. 바둑돌, 돌의 순서로 많았고, 기도에서는 땅콩 및 콩종류가 가장 많았다. 4. 연령별로는 5세이하가 64례(67.4%)였으며 특히 주화는 5세이하가 52례(92.9%)였다. 육류를 제외한 거의 모든 이물은 10세이하에서 발생하였다. 5. 년도별 및 월별분포에서는 뚜렷한 경향을 볼 수는 없었으나 최근 2년간 그 빈도가 현저히 감소하였다. 6. 식도 및 기도이물의 발생부위를 보면 식도이물은 제 1협착부에서 70례(78.7%)로 가장 많았으며, 육류는 계 2 협착부에 가장 많았으며 대부분에서 상흔협착을 동반한 경우였었다. 기도이물의 부위별 빈도는 기관지가 가장 많았으며 3 : 2로 우측에 많았다. 7. 이물의 체류기간은 1일 이내인 경우가 50례(52.6%)로 가장 많았고 한달이상 경과한 후 내원한 경우도 3례가 있었다. 8. 식도이물은 국소마취하에 83례(93.3%)는 식도경을 통하여 제거하였으나 6례(6.7%)는 제거하지 못하였다. 기도이물 6례는 모두 기관지경을 통하여 제거하였으며 이중 5세이하의 5례는 기관절개공을 통하여 제거하였다.였다. 주화의 경우 총 61례중 8례(13.1%)는 검사도중에 위속으로 내려갔다. 기도이물에서 후두이물 2례는 국소마취하에 후두경으로, 기관이물 5례중 2례(40%)는 국소마취하에 기관절개술과 함께 기관지경술로, 3례(60%)는 전신마취하에 기관지경술로 적출하였으며 기관지이물 1례는 흉부외과에서 전신마취하에 개흉술로 적출하였다.과를 매년 보고하는 한편 15년간 단속 followup할 예정이다.to-$PGF_{1{\alpha}}$생성증가 효과는 prostacyclin 합성효소억제제에 의해 길항하였다. 이상의 결과와 같이 인삼saponin 성분들은 arachidonic acid로부터 cyclooxygenase를 통해 일단 생성된 endoperoxide에서 각각의 prostaglandin을 생성하는 효소, 특히 G-$Rb_2$$TXA_2$ synthetase에 강력한 억제제로, G-Re는 prostacyclin 생합성에 촉진데로 심혈관계 균형에 기여하리라 생각된다. 발생하는 free radical을 소거할 수 있는지를 조사한 결과, free radical을 50% 소거시키는 농도값이 6 $\mu\textrm{g}$/$m\ell$로 표준물질인 비타민 C (19 $\mu\textrm{g}$/$m\ell$)나 butylated hydroxyl toluene (18.5 $\mu\textrm{g}$/$m\ell$)보다 우수한 효과를 나타내었다. 그리고 mast cell내에서 활성화되며 hyaluronic acid를 분해하는 hyaluronidase에 대한 저해를 조사한 결과, $IC_{50}$/ 값이 210 $\mu\textr

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대학생 주거관의 시계열적 비교 (Comparison on the Time series of Housing Viewpoint of University Student)