• Title/Summary/Keyword: head loss

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Mucosal Roofing Flap Reconstruction to Minimize Horizontal Lip Length Loss and Preserve Mouth Opening in Lower Lip Squamous Cell Carcinoma (아랫입술의 편평세포암 환자에서 아랫 입술 폭 손실을 최소화하고 입벌림 기능을 보존하기 위한 새로운 점막지붕 피판 재건술)

  • Jong Hyup Kim;In Chang Koh;Soo Yeon Lim;Hoon Kim
    • Korean Journal of Head & Neck Oncology
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    • v.39 no.2
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    • pp.23-26
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    • 2023
  • Lower lip reconstruction in cases with a full-thickness defect over one-third of the vermilion is challenging. Numerous conventional techniques have been applied with unsatisfactory surgical outcomes because of microstomia and oral commissure blunting due to shortened horizontal lip length. Herein, we present a case in which a full-thickness lower lip defect of more than one-third of the horizontal lip length was covered with a novel mucosal roofing flap reconstruction to minimize the loss of horizontal lip length and to preserve mouth opening. No recurrences or metastases were observed during 3 years and 6 months of follow-up, with horizontal lower lip length maintained and mouth opening of 2.5 finger breadths.

Study on the performance analysis and the optimization of regenerative pump (재생펌프의 성능해석 및 최적화에 관한 연구)

  • Lee, Chan;Sung, Hyung-Jin;Kwon, Jang-Hyuk;Chung, Myung-Kyoon
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.2
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    • pp.661-667
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    • 1991
  • A performance of a regenerative pump has been analyzed using various pressure loss correlations. The predicted head and efficiency agree favorably with experimental data, which confirms the validity of the present analysis. In addition, performance improvement is made through the optimization of the open channel geometry configuration and the capacity of the regenerative pump. The optimized pump has better efficiency, higher head and larger flow coefficient. Moreover, its operation range is wider than that of the conventional unit.

A Study on the Energy Saving through Pollutant removal of Intake gate (취수구 스크린 협잡물 제거를 통한 에너지 절감효과 분석)

  • Kim, Byeong-Kakg;Park, Inn;You, Si-Og;Jang, Seung-Don
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.930-931
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    • 2011
  • As the upsurge in oil prices and global warming, Energy saving is needed to overall industry. If The head of Intake gate screen is high. The pumping process involves a loss of energy and results in high emissions of greenhouse gases. Therefore, blockages in intake gate should be free. Another advantage of cleaning is stabilizing pumping system. Because vibration and cavitation decreases when loss of head is low.

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하수처리장 방류수를 이용한 인공함양 가능성 평가

  • 김병군;서인석;홍성택;김형수
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2002.09a
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    • pp.257-260
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    • 2002
  • The main purpose of this research is to find suitable treatment methods of wastewater effluent for artificial recharge. For this purpose, we search the effluent quality of wastewater treatment plant and possibility of additional filtration process. Particles ranged 2 ~ 5 ${\mu}{\textrm}{m}$ and 15~20 ${\mu}{\textrm}{m}$ in "T" WWTP(Waste Water Treatment Plant) effluent were relatively dominant. In dual-media filtration system operation, head-loss development of column 1 was about two times faster than column 2, and head-loss development within 5 cm from surface was very important factor in operation, Conclusively, for the stable filtration and running time of 1.5~2 day, influent turbidity must keep 5 NTU or below, and filtration system must operated at 280 m/day or below. After filtration of WWTP effluent, water quality reached satisfactory level. This water has potential of agricultural reusing, flushing water in building, recharging water to river or stream at dry season and artificial recharge of ground water.und water.

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Performance Characteristic of Regenerative Pumps (재생펌프의 성능 특성에 관한 실험적 연구)

  • Lim, Hyung-Soo;Kang, Shin-Hyoung
    • 유체기계공업학회:학술대회논문집
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    • 2003.12a
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    • pp.361-366
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    • 2003
  • For regenerative pump performance test we made 5 times enlarged and 3 different kinds blade types impeller with similarity. Due to geometrical characteristic of regenerative pump, there are two kinds of groups which effect on performance of it. One is geometric shape of impeller blade and the other is clearance and inlet/outlet head loss. To study performance of regenerative pump with impeller shape changes, we tested it with reducing clearance. And we reconcile performance data in the case of zero clearance and zero inlet/outlet head loss. Finally we could verify the influence of each group.

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A Study on the Adhesion Model of the Deposit in Rapid Filter (급속여과지에 있어서 현탁물 부착모델에 관한 연구)

  • Gang, Yong-Tae;Yu, Dong-Seon
    • 수도
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    • s.30
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    • pp.57-62
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    • 1984
  • This paper is a study on the adhesion model of the deposit in rapid filter. In this paper, ellipse adhesion model modified was proposed. With that head-loss equation during filtration that is very consistent with the experimental value was derived. In the design of the rapid filter, after this head-loss equation during filtration derived may contribute to the decision of optimum filter height.

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A Study on Vestibulosaccular Hearing (전정구형낭 청력에 관한 연구)

  • Heo, Seung-Deok
    • Phonetics and Speech Sciences
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    • v.4 no.3
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    • pp.179-186
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    • 2012
  • The aims of this study are to consider auditory physiological characteristics and to confirm audiological evaluation and interpretation in regards to cases of sensorineural hearing loss that observe an abnormal AB gap. Vestibulosaccular hearing occurs when there is an abnormally large air-bone gap (AB gap) in sensorineural hearing loss, also known as pure cochlear conductive hearing loss. Generally, an AB gap is caused by damage to the external and/or middle ear. In conductive hearing loss, loss of air condition hearing occurs due to a loss of resonance in the outer ear and/or impedance mismatching in the middle ear. Most of these types of hearing loss can be treated medically and surgically. However, there is no medical treatment for an AB gap in sensorineural hearing loss and hearing loss can worsen gradually or suddenly. In addition, many studies have reported that head trauma makes hearing loss even more serious. Therefore, in order to differentiate between conductive hearing losses, it is important to check whether or not there is an enlarged vestibular aqueduct by means of temporal bone computerized tomography and/or magnetic resonance imaging.

Late side effects of radiation treatment for head and neck cancer

  • Brook, Itzhak
    • Radiation Oncology Journal
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    • v.38 no.2
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    • pp.84-92
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    • 2020
  • Patients undergoing radiation therapy for head and neck cancer (HNC) experience significant early and long-term side effects. The likelihood and severity of complications depends on a number of factors, including the total dose of radiation delivered, over what time it was delivered and what parts of the head and neck received radiation. Late side effects include: permanent loss of saliva; osteoradionecrosis; radiation recall myositis, pharyngoesophageal stenosis; dental caries; oral cavity necrosis; fibrosis; impaired wound healing; skin changes and skin cancer; lymphedema; hypothyroidism, hyperparathyroidism, lightheadedness, dizziness and headaches; secondary cancer; and eye, ear, neurological and neck structures damage. Patients who undergo radiotherapy for nasopharyngeal carcinoma tend to suffer from chronic sinusitis. These side effects present difficult challenges to the patients and their caregivers and require life-long strategies to alleviate their deleterious effect on basic life functions and on the quality of life. This review presents these side effects and their management.

A Case of Langerhans Cell Histiocytosis involving the External Auditory Canal (외이도에 발생한 랑게르한스 세포 조직구증 1예)

  • Seo, Yoon Soo;Lee, Hwan Ho
    • Korean Journal of Head & Neck Oncology
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    • v.37 no.2
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    • pp.67-69
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    • 2021
  • Langerhans cell histiocytosis (LCH) is commonly characterized by abnormal function and differentiation or proliferation of monocytes. In LCH, granulomatous lesions, including langerine-positive histocytes and inflammatory infiltrates, can occur to all tissues, particularly well in the bones, skin, lungs, and pituitary gland. In case of external auditory canal LCH, conductive hearing loss may occur, and the most common symptom is otorrhea. Here we present a case that 49-year-old male with external auditory canal mass. Since no invasive findings were seen in radiologic study, endoscopic transcanal excision was performed and LCH was proven by pathologic report. We present this case of external auditory canal LCH with the review of literature.

Precise segmentation of fetal head in ultrasound images using improved U-Net model

  • Vimala Nagabotu;Anupama Namburu
    • ETRI Journal
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    • v.46 no.3
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    • pp.526-537
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    • 2024
  • Monitoring fetal growth in utero is crucial to anomaly diagnosis. However, current computer-vision models struggle to accurately assess the key metrics (i.e., head circumference and occipitofrontal and biparietal diameters) from ultrasound images, largely owing to a lack of training data. Mitigation usually entails image augmentation (e.g., flipping, rotating, scaling, and translating). Nevertheless, the accuracy of our task remains insufficient. Hence, we offer a U-Net fetal head measurement tool that leverages a hybrid Dice and binary cross-entropy loss to compute the similarity between actual and predicted segmented regions. Ellipse-fitted two-dimensional ultrasound images acquired from the HC18 dataset are input, and their lower feature layers are reused for efficiency. During regression, a novel region of interest pooling layer extracts elliptical feature maps, and during segmentation, feature pyramids fuse field-layer data with a new scale attention method to reduce noise. Performance is measured by Dice similarity, mean pixel accuracy, and mean intersection-over-union, giving 97.90%, 99.18%, and 97.81% scores, respectively, which match or outperform the best U-Net models.